Fix black frame when unlocking device via clicking on notification

- Make sure to tell the app to start drawing if it has been stopped, app
  could be stopped in visible state.

- When activity is started with NEW_TASK + CLEAR_TASK flags, skip
  resuming of the soon-to-be-removed activity, and run enter animation
  directly on the new activity. Resuming the old activity causes delay,
  and we also run extra enter-exit transition in short succession which
  cause glitches.

bug: 27391256
Change-Id: I390ef9fc9855d70a4a9642c06c87cbe548b8b466