Changes the vibrator_manager shell commands to block until the end of

the vibration by default, and adds a -B option to give the old behaviour
of just initiating the vibration.

This has the side effect of cancelling the vibration if the adb command
is cancelled, which is useful default behavior for repeating vibrations.

The change also introduces slightly more robust cancellation of
mNextVibration, which may previously have missed some dropped vibrations
- these are now recorded with a new status of IGNORED_SUPERSEDED.

Change-Id: Ibf0eb72a71a6793370317f4e14210f5899d5f5c9
Test: manual adb commands
Bug: 127483176