Add IDisplayEventReceiver interface.

Note, three layered interface is required because neither
Bn nor Bp hidl objects are guaranteed to be the same, so
you can't compare interfaces. (38348572, 32172906).

This interface makes vsync data available to vendor hals.

Test: VtsFwkDisplayServiceV1_0TargetTest
Bug: 38311538
Change-Id: I570f7e6e73dbc0b82d6743302da36d073c6a06fe