[automerge] Revert "Revert "RESTRICT AUTOMERGE Set BUILD_ID=SC"" 2p: ef1bcc1f9a

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/15798253

Bug: 196178071
Change-Id: Ia03cf697f157a36ad6d0d438d5f901376924e750