Update Accessibility vibration settings.

- Get notification vibration and haptic feedback intensity respectively.
- Use xliffs to compose these strings.
- Use the version that passed in Vibrator.class to get Vibrator
  instance.
- Refactor switch/case part in getSummary() of
  VibrationIntensityPreferenceController.
  Let AccessibilitySettings and VibrationIntensityPreferenceController
  both call it.
- Add robolectric test for method: updateVibrationSummary().
- Refine test method, use real preference and test summary value.
- Remove redundancy.

Bug: 75322064
Test: make ROBOTEST_FILTER=AccessibilitySettingsTest RunSettingsRoboTests
Change-Id: Ia3c7447b1ab1e336b36ad439800b673821417e48
Merged-In: Ia3c7447b1ab1e336b36ad439800b673821417e48