Merge "Add @Nullable to SensorManager.getDefaultSensor's return value" am: 29aa6b8a72 am: 64a8b8356f am: 454a300294

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2377608

Change-Id: I6e40e6e2b620b8d03884770fcbe5fcdacd17c754
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>