Create soong config to support other apis for aconfig finalization

Bug: b/391174731
Flag: NONE exempt build change
Test: `m all_aconfig_declarations` and check finalized-flags.txt
Ignore-AOSP-First: testing in main presubmits, will cp
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a901751cea47a035e9bb6a0bb35ac2ba324b335d)
Merged-In: I8612b185db60085a3be3fc560fc11cf77fbf35db
Change-Id: I8612b185db60085a3be3fc560fc11cf77fbf35db