VTS to use enum for MissingAction am: 84187967cb am: 37813dbd44

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2909582

Change-Id: I11ab91c91378f51c837723df1250db8ab6604b44
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>