Add setting to control vibration intensity.

This patch adds two distinct vibration control settings: one for
notifications and ringtones, and one for haptic feedback. Since we don't
always have the exact intent of a given vibration, VibratorService will
do its best to classify each VibrationEffect into one of these two
categories and then scale the vibration accordingly based on the
intensity setting.

Bug: 64185329
Test: cts-tradefed run commandAndExit cts-dev -m CtsOsTestCases -t android.os.cts.VibratorTest
      cts-tradefed run commandAndExit cts-dev -m CtsOsTestCases -t android.os.cts.VibrationEffectTest
Change-Id: If16237f4782281aaab33e4a0f55c29f1a30ac493