Add FSTAB_OWNERS and update OWNERS to include Android.bp am: 70b62a2bcd am: 7c84d4f5d8

Original change: https://android-review.googlesource.com/c/device/google/gs-common/+/3205326

Change-Id: I6dd88ed20fd36d030c05d521c354924f82755378
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>