Merge "Document changes and clean up spec" am: 4ad2bb150e am: 48a0aa8a11

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2308373

Change-Id: I68aabcffefaf76bbaf8203b9def6d76b668d8733
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>