Update vibration cancellation policy for notifications

Touch feedback vibration (e.g. keyboard tap feedback) is consistently
cancelling ongoing notification vibrations, which creates a user
perceivable strange effect when a longer waveform is consistently
cancelled by the shorter click effect.

The notification vibrations in general should have a higher priority,
similar to rigtone and alarm vibrations, and not be cancelled when
lower priority vibrations like touch feedback are triggered.

Updating the prioritization to the following:

ringtone > alarm > notification > a11y > hardware feedbacks > others

Fix: 234100304
Test: VibrationManagerServiceTest
Change-Id: I6e356430d66cf0ea7403e0eb270dbdf6a13af0b9