Validate request metadata before coverting to camera metadata am: df9ea6e679 am: eb30591704

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/20918704

Change-Id: Idbcb93a0b767f90023d7179021ab3959b4be49cb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>