Add new .ahv MIME type for VibrationEffect files

Media type name: application
Media subtype name: vnd.android.haptics.vibration+xml

Introduce new MIME type for xml files representing vibration effects, as
specified by the schema at core/xsd/vibrator/vibration/vibration.xsd.

Fix: 284268315
Test: atest CtsLibcoreTestCases:libcore.libcore.net.MimeMapTest
Change-Id: I45f06cb04d06a04e292e505ea88004f868b5be64