[automerger skipped] Merge "Hide start and cancel handover from api surface"...

[automerger skipped] Merge "Hide start and cancel handover from api surface" am: ee4668c5 am: 42b6ecf0 am: a57b0042 -s ours am: 596e2595 -s ours

am skip reason: Change-Id I9e65ad178a843e92a59e5e4f7debd4d7b77a3edb with SHA-1 fa1cf3d5 is in history

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1598495

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I505acabb7f6b02136123b76103923e50d6818b24