Extend lifetime of notifs during activity launch

Clicking on a notification can result in a chain of asynchronous
code, depending on the state of the shade and keyguard. If the
notification that was clicked is cancelled during this async flow, then
when it's finally complete, if the notification has FLAG_AUTO_CANCEL,
SystemUI will attempt to dismiss the notification, which is no longer
there according to the pipeline, due to the aforementioned cancellation.

This CL fixes the issue by introducing a new
ActivityLaunchAnimCoordinater that registers a lifetime extender to keep
notifications alive during their launch animation.

Fixes: 219939676

Test: atest SystemUITests
Test: 1. Install Notify.apk (go/notify-apk)
      2. In the Notify app: Check off Delayed 5000 and Auto Cancel
      3. Click "Add" and spam click "Update" (5-10 times should suffice)
      4. Expand notification shade
      5. Immediately tap the Notify notification when it gets posted
      Observe: no crashing

Change-Id: I819ad840845df1bfa3acd71187c6ba47de9a64b7