diff --git a/tools/aconfig/aconfig/src/codegen/java.rs b/tools/aconfig/aconfig/src/codegen/java.rs
index 61802f2..d74e87a 100644
--- a/tools/aconfig/aconfig/src/codegen/java.rs
+++ b/tools/aconfig/aconfig/src/codegen/java.rs
@@ -59,7 +59,8 @@
     let runtime_lookup_required =
         flag_elements.iter().any(|elem| elem.is_read_write) || library_exported;
     let container = (flag_elements.first().expect("zero template flags").container).to_string();
-    let is_platform_container = matches!(container.as_str(), "system" | "product" | "vendor");
+    let is_platform_container =
+        matches!(container.as_str(), "system" | "system_ext" | "product" | "vendor");
     let context = Context {
         flag_elements,
         namespace_flags,
diff --git a/tools/aconfig/exported_flag_check/allow_list.txt b/tools/aconfig/exported_flag_check/allow_list.txt
index e69de29..b9c81c4 100644
--- a/tools/aconfig/exported_flag_check/allow_list.txt
+++ b/tools/aconfig/exported_flag_check/allow_list.txt
@@ -0,0 +1,260 @@
+android.adpf.adpf_viewrootimpl_action_down_boost
+android.app.admin.flags.coexistence_migration_for_supervision_enabled
+android.app.admin.flags.enable_supervision_service_sync
+android.app.admin.flags.lock_now_coexistence
+android.app.admin.flags.permission_migration_for_zero_trust_api_enabled
+android.app.admin.flags.reset_password_with_token_coexistence
+android.app.admin.flags.set_application_restrictions_coexistence
+android.app.admin.flags.set_backup_service_enabled_coexistence
+android.app.admin.flags.set_keyguard_disabled_features_coexistence
+android.app.admin.flags.set_permission_grant_state_coexistence
+android.app.app_restrictions_api
+android.app.enforce_pic_testmode_protocol
+android.app.job.backup_jobs_exemption
+android.app.pic_uses_shared_memory
+android.app.pinner_service_client_api
+android.app.supervision.flags.deprecate_dpm_supervision_apis
+android.app.supervision.flags.enable_sync_with_dpm
+android.app.supervision.flags.supervision_api
+android.app.supervision.flags.supervision_api_on_wear
+android.app.ui_rich_ongoing
+android.appwidget.flags.use_smaller_app_widget_system_radius
+android.car.feature.always_send_initial_value_event
+android.car.feature.android_b_vehicle_properties
+android.car.feature.android_vic_vehicle_properties
+android.car.feature.area_id_config_access
+android.car.feature.async_audio_service_init
+android.car.feature.audio_control_hal_configuration
+android.car.feature.audio_legacy_mode_navigation_volume
+android.car.feature.audio_vendor_freeze_improvements
+android.car.feature.batched_subscriptions
+android.car.feature.car_app_card
+android.car.feature.car_audio_dynamic_devices
+android.car.feature.car_audio_fade_manager_configuration
+android.car.feature.car_audio_min_max_activation_volume
+android.car.feature.car_audio_mute_ambiguity
+android.car.feature.car_evs_query_service_status
+android.car.feature.car_evs_stream_management
+android.car.feature.car_night_global_setting
+android.car.feature.car_power_cancel_shell_command
+android.car.feature.car_property_detailed_error_codes
+android.car.feature.car_property_supported_value
+android.car.feature.car_property_value_property_status
+android.car.feature.cluster_health_monitoring
+android.car.feature.display_compatibility
+android.car.feature.handle_property_events_in_binder_thread
+android.car.feature.persist_ap_settings
+android.car.feature.projection_query_bt_profile_inhibit
+android.car.feature.serverless_remote_access
+android.car.feature.subscription_with_resolution
+android.car.feature.supports_secure_passenger_users
+android.car.feature.switch_user_ignoring_uxr
+android.car.feature.variable_update_rate
+android.car.feature.visible_background_user_restrictions
+android.companion.new_association_builder
+android.companion.ongoing_perm_sync
+android.companion.virtualdevice.flags.camera_multiple_input_streams
+android.companion.virtualdevice.flags.notifications_for_device_streaming
+android.content.pm.get_package_storage_stats
+android.content.res.layout_readwrite_flags
+android.content.res.resources_minor_version_support
+android.content.res.rro_control_for_android_no_overlayable
+android.content.res.self_targeting_android_resource_frro
+android.content.res.system_context_handle_app_info_changed
+android.credentials.flags.settings_activity_enabled
+android.hardware.biometrics.screen_off_unlock_udfps
+android.hardware.devicestate.feature.flags.device_state_property_migration
+android.hardware.devicestate.feature.flags.device_state_rdm_v2
+android.hardware.devicestate.feature.flags.device_state_requester_cancel_state
+android.hardware.usb.flags.enable_interface_name_device_filter
+android.hardware.usb.flags.enable_is_mode_change_supported_api
+android.media.audio.focus_exclusive_with_recording
+android.media.audio.focus_freeze_test_api
+android.media.audio.foreground_audio_control
+android.media.audio.hardening_permission_api
+android.media.audio.hardening_permission_spa
+android.media.audio.ro_foreground_audio_control
+android.media.audiopolicy.audio_mix_test_api
+android.media.codec.aidl_hal_input_surface
+android.media.swcodec.flags.apv_software_codec
+android.media.swcodec.flags.mpeg2_keep_threads_active
+android.media.tv.flags.enable_le_audio_broadcast_ui
+android.media.tv.flags.enable_le_audio_unicast_ui
+android.media.tv.flags.hdmi_control_collect_physical_address
+android.media.tv.flags.hdmi_control_enhanced_behavior
+android.media.tv.flags.tif_unbind_inactive_tis
+android.multiuser.enable_biometrics_to_unlock_private_space
+android.net.platform.flags.mdns_improvement_for_25q2
+android.nfc.nfc_persist_log
+android.nfc.nfc_watchdog
+android.os.adpf_graphics_pipeline
+android.os.android_os_build_vanilla_ice_cream
+android.os.battery_saver_supported_check_api
+android.os.network_time_uses_shared_memory
+android.os.profiling.persist_queue
+android.os.profiling.redaction_enabled
+android.permission.flags.allow_host_permission_dialogs_on_virtual_devices
+android.permission.flags.device_aware_permissions_enabled
+android.permission.flags.device_policy_management_role_split_create_managed_profile_enabled
+android.permission.flags.enable_aiai_proxied_text_classifiers
+android.permission.flags.enable_otp_in_text_classifiers
+android.permission.flags.enable_sqlite_appops_accesses
+android.permission.flags.location_bypass_privacy_dashboard_enabled
+android.permission.flags.note_op_batching_enabled
+android.permission.flags.permission_request_short_circuit_enabled
+android.permission.flags.rate_limit_batched_note_op_async_callbacks_enabled
+android.permission.flags.sensitive_notification_app_protection
+android.permission.flags.supervision_role_permission_update_enabled
+android.permission.flags.unknown_call_package_install_blocking_enabled
+android.permission.flags.updatable_text_classifier_for_otp_detection_enabled
+android.permission.flags.use_profile_labels_for_default_app_section_titles
+android.permission.flags.wallet_role_cross_user_enabled
+android.provider.allow_config_maximum_call_log_entries_per_sim
+android.provider.backup_tasks_settings_screen
+android.provider.flags.new_storage_writer_system_api
+android.service.autofill.fill_dialog_improvements_impl
+android.service.chooser.fix_resolver_memory_leak
+android.service.notification.redact_sensitive_notifications_big_text_style
+android.service.notification.redact_sensitive_notifications_from_untrusted_listeners
+android.view.accessibility.motion_event_observing
+android.view.flags.expected_presentation_time_api
+android.view.flags.toolkit_frame_rate_touch_boost_25q1
+android.view.inputmethod.concurrent_input_methods
+android.view.inputmethod.ime_switcher_revamp
+android.view.inputmethod.imm_userhandle_hostsidetests
+android.webkit.mainline_apis
+android.widget.flags.use_wear_material3_ui
+com.android.aconfig.test.disabled_rw_exported
+com.android.aconfig.test.enabled_fixed_ro_exported
+com.android.aconfig.test.enabled_ro_exported
+com.android.aconfig.test.exported.exported_flag
+com.android.aconfig.test.forcereadonly.fro_exported
+com.android.adservices.ondevicepersonalization.flags.on_device_personalization_apis_enabled
+com.android.appsearch.flags.app_open_event_indexer_enabled
+com.android.appsearch.flags.apps_indexer_enabled
+com.android.appsearch.flags.enable_app_functions_schema_parser
+com.android.appsearch.flags.enable_apps_indexer_incremental_put
+com.android.appsearch.flags.enable_contacts_index_first_middle_and_last_names
+com.android.appsearch.flags.enable_document_limiter_replace_tracking
+com.android.appsearch.flags.enable_enterprise_empty_batch_result_fix
+com.android.bluetooth.flags.allow_switching_hid_and_hogp
+com.android.bluetooth.flags.bt_offload_socket_api
+com.android.bluetooth.flags.channel_sounding
+com.android.bluetooth.flags.fix_started_module_race
+com.android.bluetooth.flags.le_subrate_api
+com.android.bluetooth.flags.leaudio_broadcast_monitor_source_sync_status
+com.android.bluetooth.flags.leaudio_broadcast_volume_control_for_connected_devices
+com.android.bluetooth.flags.leaudio_multiple_vocs_instances_api
+com.android.bluetooth.flags.metadata_api_inactive_audio_device_upon_connection
+com.android.bluetooth.flags.settings_can_control_hap_preset
+com.android.bluetooth.flags.unix_file_socket_creation_failure
+com.android.graphics.flags.icon_load_drawable_return_null_when_uri_decode_fails
+com.android.graphics.hwui.flags.animated_image_drawable_filter_bitmap
+com.android.hardware.input.manage_key_gestures
+com.android.healthfitness.flags.activity_intensity_db
+com.android.healthfitness.flags.add_missing_access_logs
+com.android.healthfitness.flags.architecture_improvement
+com.android.healthfitness.flags.cloud_backup_and_restore
+com.android.healthfitness.flags.cycle_phases
+com.android.healthfitness.flags.d2d_file_deletion_bug_fix
+com.android.healthfitness.flags.dependency_injection
+com.android.healthfitness.flags.development_database
+com.android.healthfitness.flags.ecosystem_metrics
+com.android.healthfitness.flags.ecosystem_metrics_db_changes
+com.android.healthfitness.flags.export_import
+com.android.healthfitness.flags.export_import_fast_follow
+com.android.healthfitness.flags.export_import_nice_to_have
+com.android.healthfitness.flags.expressive_theming_enabled
+com.android.healthfitness.flags.health_connect_mappings
+com.android.healthfitness.flags.immediate_export
+com.android.healthfitness.flags.logcat_censor_iae
+com.android.healthfitness.flags.new_information_architecture
+com.android.healthfitness.flags.onboarding
+com.android.healthfitness.flags.permission_metrics
+com.android.healthfitness.flags.permission_tracker_fix_mapping_init
+com.android.healthfitness.flags.personal_health_record_database
+com.android.healthfitness.flags.personal_health_record_disable_d2d
+com.android.healthfitness.flags.personal_health_record_disable_export_import
+com.android.healthfitness.flags.personal_health_record_enable_d2d_and_export_import
+com.android.healthfitness.flags.personal_health_record_entries_screen
+com.android.healthfitness.flags.personal_health_record_lock_screen_banner
+com.android.healthfitness.flags.personal_health_record_telemetry
+com.android.healthfitness.flags.personal_health_record_telemetry_private_ww
+com.android.healthfitness.flags.personal_health_record_ui_telemetry
+com.android.healthfitness.flags.phr_fhir_basic_complex_type_validation
+com.android.healthfitness.flags.phr_fhir_complex_type_validation
+com.android.healthfitness.flags.phr_fhir_oneof_validation
+com.android.healthfitness.flags.phr_fhir_primitive_type_validation
+com.android.healthfitness.flags.phr_fhir_structural_validation
+com.android.healthfitness.flags.phr_read_medical_resources_fix_query_limit
+com.android.healthfitness.flags.phr_upsert_fix_parcel_size_calculation
+com.android.healthfitness.flags.phr_upsert_fix_use_shared_memory
+com.android.icu.icu_v_api
+com.android.internal.telephony.flags.async_init_carrier_privileges_tracker
+com.android.internal.telephony.flags.cleanup_carrier_app_update_enabled_state_logic
+com.android.internal.telephony.flags.oem_enabled_satellite_phase_2
+com.android.internal.telephony.flags.remap_disconnect_cause_sip_request_cancelled
+com.android.libcore.hpke_v_apis
+com.android.libcore.read_only_dynamic_code_load
+com.android.libcore.v_apis
+com.android.media.audio.hardening_impl
+com.android.media.audio.hardening_strict
+com.android.media.extractor.flags.extractor_mp4_enable_apv
+com.android.media.extractor.flags.extractor_sniff_midi_optimizations
+com.android.media.flags.enable_cross_user_routing_in_media_router2
+com.android.media.flags.enable_notifying_activity_manager_with_media_session_status_change
+com.android.media.metrics.flags.mediametrics_to_module
+com.android.media.projection.flags.media_projection_connected_display
+com.android.media.projection.flags.media_projection_connected_display_no_virtual_device
+com.android.net.ct.flags.certificate_transparency_job
+com.android.net.ct.flags.certificate_transparency_service
+com.android.net.flags.restrict_local_network
+com.android.net.flags.tethering_active_sessions_metrics
+com.android.net.thread.flags.thread_mobile_enabled
+com.android.nfc.module.flags.nfc_hce_latency_events
+com.android.org.conscrypt.flags.certificate_transparency_checkservertrusted_api
+com.android.permission.flags.add_banners_to_privacy_sensitive_apps_for_aaos
+com.android.permission.flags.app_permission_fragment_uses_preferences
+com.android.permission.flags.archiving_read_only
+com.android.permission.flags.decluttered_permission_manager_enabled
+com.android.permission.flags.enable_coarse_fine_location_prompt_for_aaos
+com.android.permission.flags.enhanced_confirmation_backport_enabled
+com.android.permission.flags.expressive_design_enabled
+com.android.permission.flags.livedata_refactor_permission_timeline_enabled
+com.android.permission.flags.odad_notifications_supported
+com.android.permission.flags.permission_timeline_attribution_label_fix
+com.android.permission.flags.private_profile_supported
+com.android.permission.flags.safety_center_enabled_no_device_config
+com.android.permission.flags.safety_center_issue_only_affects_group_status
+com.android.permission.flags.wear_compose_material3
+com.android.permission.flags.wear_privacy_dashboard_enabled_read_only
+com.android.providers.contactkeys.flags.contactkeys_strip_fix
+com.android.providers.media.flags.enable_backup_and_restore
+com.android.providers.media.flags.enable_malicious_app_detector
+com.android.providers.media.flags.enable_mark_media_as_favorite_api
+com.android.providers.media.flags.enable_modern_photopicker
+com.android.providers.media.flags.enable_photopicker_search
+com.android.providers.media.flags.enable_photopicker_transcoding
+com.android.providers.media.flags.enable_stable_uris_for_external_primary_volume
+com.android.providers.media.flags.enable_stable_uris_for_public_volume
+com.android.providers.media.flags.enable_unicode_check
+com.android.providers.media.flags.index_media_latitude_longitude
+com.android.providers.media.flags.version_lockdown
+com.android.ranging.flags.ranging_stack_updates_25q4
+com.android.server.backup.enable_read_all_external_storage_files
+com.android.server.telecom.flags.allow_system_apps_resolve_voip_calls
+com.android.server.telecom.flags.telecom_app_label_proxy_hsum_aware
+com.android.server.telecom.flags.telecom_main_user_in_block_check
+com.android.server.telecom.flags.telecom_main_user_in_get_respond_message_app
+com.android.server.updates.certificate_transparency_installer
+com.android.system.virtualmachine.flags.terminal_gui_support
+com.android.tradeinmode.flags.enable_trade_in_mode
+com.android.update_engine.minor_changes_2025q4
+com.android.uwb.flags.uwb_fira_3_0_25q4
+com.android.wifi.flags.network_provider_battery_charging_status
+com.android.wifi.flags.p2p_dialog2
+com.android.wifi.flags.shared_connectivity_broadcast_receiver_test_api
+com.android.wifi.flags.wep_disabled_in_apm
+com.android.window.flags.untrusted_embedding_state_sharing
+vendor.vibrator.hal.flags.enable_pwle_v2
+vendor.vibrator.hal.flags.remove_capo
\ No newline at end of file
diff --git a/tools/aconfig/fake_device_config/src/android/os/Build.java b/tools/aconfig/fake_device_config/src/android/os/Build.java
index 790ff82..8ec72fb 100644
--- a/tools/aconfig/fake_device_config/src/android/os/Build.java
+++ b/tools/aconfig/fake_device_config/src/android/os/Build.java
@@ -18,9 +18,6 @@
 
 public class Build {
     public static class VERSION {
-        public static final int SDK_INT = placeholder();
-        private static int placeholder() {
-            throw new UnsupportedOperationException("Stub!");
-        }
+        public static final int SDK_INT = 0;
     }
 }
diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py
index b6c96c4..08b4d6a 100755
--- a/tools/releasetools/build_image.py
+++ b/tools/releasetools/build_image.py
@@ -49,8 +49,8 @@
 # Use a fixed timestamp (01/01/2009 00:00:00 UTC) for files when packaging
 # images. (b/24377993, b/80600931)
 FIXED_FILE_TIMESTAMP = int((
-    datetime.datetime(2009, 1, 1, 0, 0, 0, 0, None) -
-    datetime.datetime.utcfromtimestamp(0)).total_seconds())
+    datetime.datetime(2009, 1, 1, 0, 0, 0, 0, datetime.UTC) -
+    datetime.datetime.fromtimestamp(0, datetime.UTC)).total_seconds())
 
 
 class BuildImageError(Exception):
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index b6cbb15..e5f5f92 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -2993,7 +2993,7 @@
     os.chmod(filename, perms)
 
     # Use a fixed timestamp so the output is repeatable.
-    # Note: Use of fromtimestamp rather than utcfromtimestamp here is
+    # Note: Use of fromtimestamp without specifying a timezone here is
     # intentional. zip stores datetimes in local time without a time zone
     # attached, so we need "epoch" but in the local time zone to get 2009/01/01
     # in the zip archive.