[automerger skipped] Enable mainline prebuilts on tm-dev branch. am:...

[automerger skipped] Enable mainline prebuilts on tm-dev branch. am: de9f0b12 -s ours am: b0ae70b3 -s ours

am skip reason: Merged-In I9731400acfade95b3eab8f2d99fddb4cf856aa91 with SHA-1 4a71082e is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/18467382



Change-Id: I4fc8c5f352c0f8a34a5e1a51aa321b809fa5c60c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>