Rename CombinedVibrationEffect to CombinedVibration

The change makes the distinction between VibrationEffect and
CombinedVibratio clearer. The later is a combination of the former with
the extra information about the vibrator ids, allowing effects to be
played in one or more vibrators in parallel or in sequence.

The methods create/start synced where also renamed to parallel (together
with respective builder classes), to indicate they perform one or more
effects in parallel on multiple vibrators. This is also a better match
to the sequential combinations.

This change also deprecates the Context.VIBRATOR_SERVICE in favour of
the new VIBRATOR_MANAGER_SERVICE. The default vibrator can be retrieved
from the manager system service.

Same deprecation applied to InputDevice.getVibrator method.

Fix: 184123900
Test: CombinedVibrationTest
Change-Id: I44d8b225098d35fbf7783254acaf6a78f9fb4505