[DO NOT MERGE] Handle unavailable properties

Accommodate the case in which `set()` for an unavailable property is
called as the VHAL may return OK or NOT_AVAILABLE.

Also, it may be the case that certain properties aren't available
while testing and thus, setting a value and getting it right after
might not always work.

Bug: 290882809
Change-Id: I7b7b3f144c4fbd786bf673a86fcac110ec8f79b5