[automerger skipped] Add PLATFORM_VERSION_LAST_STABLE to soong config am: 788648f6 -s ours

am skip reason: Merged-In Iec36d22af80225f6da848bae1e02d263ff957df8 with SHA-1 a59b4dcd is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/17944026



Change-Id: I83a2962e695b379c2cb39d2842406713aec725d9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>