Revert^2 "Add soong config variable Release_expose_flagged_api"

This reverts commit 453d74ba4899066b840db6105bdc574c1dce51c1.

Change-Id: Ic5cc83ebe396ccf05b51b8306b79a61dbb689807
diff --git a/core/soong_config.mk b/core/soong_config.mk
index e3eb780..52bcd9a 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -40,7 +40,9 @@
 $(call add_json_str,  Platform_base_os,                  $(PLATFORM_BASE_OS))
 $(call add_json_str,  Platform_version_last_stable,      $(PLATFORM_VERSION_LAST_STABLE))
 $(call add_json_str,  Platform_version_known_codenames,  $(PLATFORM_VERSION_KNOWN_CODENAMES))
+
 $(call add_json_bool, Release_aidl_use_unfrozen,         $(RELEASE_AIDL_USE_UNFROZEN))
+$(call add_json_bool, Release_expose_flagged_api,        $(RELEASE_EXPOSE_FLAGGED_API))
 
 $(call add_json_str,  Platform_min_supported_target_sdk_version, $(PLATFORM_MIN_SUPPORTED_TARGET_SDK_VERSION))