Merge "Support showing transient bars upon 3-finger swipe from trackpad" into...

Merge "Support showing transient bars upon 3-finger swipe from trackpad" into udc-qpr-dev am: e1467ef5 am: 521c731b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23578798



Change-Id: I74ee88957016ff460067c3b1bf64bbdb6549b46d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>