[automerger skipped] Add RootTargetPreparer for explicitly specifying the root...

[automerger skipped] Add RootTargetPreparer for explicitly specifying the root dependency am: fb283ce5 am: 8b1efdc4 am: cfbb9d94 am: 2ae19061 am: 18c1440c am: 9ac30506 am: a92592d6 am: 9bef2f12 -s ours

am skip reason: Merged-In I4b86fd5ee31f746942a2bf073a29cb2180a39f27 with SHA-1 76aa9d6a is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/26681387



Change-Id: Ia228863c93b5902eb0f905c82571c05c441122a0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>