Backup & restore for ringtone vibrations

After CL[1] and CL[2], the ringtone/notification
support custome vibration playback.

If the user choose ringtone/notification with a
vibration, backup original value and use the same
value directly for restoring.

[1]: I8fc4f49e3801caec1dc2b0b611dd5b3854c6395f
[2]: I864c42b5c30f41328633bd37fe8fb571fb9cdbe4

Flag: android.media.audio.enable_ringtone_haptics_customization
Bug: 358525300
Bug: 371474327
Bug: 371471679
Test: atest SettingsHelperTest
Test: Set up a ringtone with a vibration -> Backup the settings
-> Factory reset the device -> Restore the settings from the same
user -> Verify the ringtone and vibration are restored
Change-Id: I0ff20125baf2b0df225f25439c849cd7aee90a72

Change-Id: Ic15a2912becccf53e44188d8ae26bd683bb2f1cf