Merge "Add TRACKPAD_GESTURE_BACK flag" into tm-qpr-dev am: a780fc4b47 am: 5d77936d7d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20839834

Change-Id: I7174e57c8752ca2e33a109959b92bc6f1d43647b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>