vsyncId should always be incremental

In some conditions of scheduling delays, Choreographer may
synthetically advance the indented vsync time. In that case we can't
send a vsync id since there is no one that corresponds to that time.

Test: TBD
Bug: 191840734
Change-Id: I7b2754d5dcb0a3f5fd6cda00a3a2469041116f67