Revert "Replace system_ext container with system"

This reverts commit 2082a209aabfa433044f4a2ebee76d2ea477cfcb.

A system partition cannot have the aconfigs of other partitions.
Revive the system_ext container for system_ext aconfigs.

Bug: 385213580
Test: "adb shell aflags list" must not be changed.
Flag: EXEMPT refactor
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:c7b542941e72747771bc6970c8674ffccc0ccced)
Merged-In: Ib3a533493060948035c393e83a1a260fdc380624
Change-Id: Ib3a533493060948035c393e83a1a260fdc380624
diff --git a/services/foldables/devicestateprovider/src/com/android/server/policy/feature/Android.bp b/services/foldables/devicestateprovider/src/com/android/server/policy/feature/Android.bp
index 6393e11..1db9e8d 100644
--- a/services/foldables/devicestateprovider/src/com/android/server/policy/feature/Android.bp
+++ b/services/foldables/devicestateprovider/src/com/android/server/policy/feature/Android.bp
@@ -1,7 +1,7 @@
 aconfig_declarations {
     name: "device_state_flags",
     package: "com.android.server.policy.feature.flags",
-    container: "system",
+    container: "system_ext",
     srcs: [
         "device_state_flags.aconfig",
     ],
diff --git a/services/foldables/devicestateprovider/src/com/android/server/policy/feature/device_state_flags.aconfig b/services/foldables/devicestateprovider/src/com/android/server/policy/feature/device_state_flags.aconfig
index 21e33dd..f827b55 100644
--- a/services/foldables/devicestateprovider/src/com/android/server/policy/feature/device_state_flags.aconfig
+++ b/services/foldables/devicestateprovider/src/com/android/server/policy/feature/device_state_flags.aconfig
@@ -1,5 +1,5 @@
 package: "com.android.server.policy.feature.flags"
-container: "system"
+container: "system_ext"
 
 flag {
     name: "enable_dual_display_blocking"