Introduce alarm and media vibration intensity settings

Introduce toggles and sliders to configure the alarm and media
vibrations in the "Vibration & haptics" settings app.

Also update the multiple intensities configuration flag into a integer,
where the device can specify how many distinct levels are supported.
Follow existing implementation to map the intensities to higher setting
values.

Bug: 198346559
Bug: 207477604
Test: [Alarm|Media]Vibration[Intensity|Toggle]PreferenceControllerTest
Change-Id: Ie3d570b72ba1229e613ecf0c45fac81233529e32