Merge "Drop some special casing of source vs prebuilt mainline selection" into...

Merge "Drop some special casing of source vs prebuilt mainline selection" into main am: bd7435ad am: 4d18fbb1

Original change: https://android-review.googlesource.com/c/platform/build/+/3032226



Change-Id: I0d7f783e26b1819ac2633a3e1ed3f03e97944b9f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>