Add APIs in PowerManager for suppressing ambient display.

Added 4 methods:
boolean isAmbientDisplayAvailable()
void suppressAmbientDisplay(String token, boolean suppress)
boolean isAmbientDisplaySuppressedForToken(String token)
boolean isAmbientDisplaySuppressed()

This CL simply adds the API to toggle SUPPRESS_DOZE. The code for
actually turning off doze when the secure setting is updated will be
implemented in a follow-up CL.

Test: manual, atest FrameworksServicesTests:PowerManagerServiceTest
Bug: 147584235, 147587449
Change-Id: I54f46f75fb84aae2ae806690e73eeb427ad8e8e1