DO NOT MERGE Add SEAT_HEADREST_* properties to the emulator for am: 34e7cd0557

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/19628774

Change-Id: If17806bdbfd6215cb7d29a392e6e1c4174e5fbfb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>