do wom: fix potential issue of VirtualDisplay's callback not called

- Remove requestDisplayStateLocked version without displayoffload &
  enforce VirtualDisplayAdapter to implement the new
  requestDisplayStateLocked.
- Fix tests.

Test: atest DisplayManagerServiceTest && atest LocalDisplayAdapterTest
BUG: 304944369
Change-Id: I1ec351e6280088b301662cdb0af6ad24f84fc93e