Update Settings to use intensity settings as main preference keys

Updating the Settings app to allow setting the value off for key
HAPTIC_FEEDBACK_INTENSITY. This setting state is also copied onto
HAPTIC_FEEDBACK_ENABLED setting, so both should be in sync after this
change.

Similar logic is applied between RING_VIBRATION_INTENSITY and
VIBRATE_WHEN_RINGING.

This will not disable the hardware feedback since that one is controlled
by a separate setting key now.

The "vibrate for calls" was also removed and the single toggle for
"vibrate first then ring gradually" was moved into the "Vibration &
haptics" page.

Bug: 185351540
Test: [HapticFeedback|NotificationVibration|RingVibration][Intensity|Toggle]PreferenceControllerTest
      and manual testing of the AOSP settings app
Change-Id: I9c94cef331a1500a1272a601ba32667ca995ddab