Extract vibrator service tests from FrameworksServicesTests

Move all tests for package com.android.server.vibrator from
frameworks/base/services/tests/servicestests to a new folder
frameworks/base/services/tests/vibratorservicestests.

Create a new private java library for test utility classes in a new
folder vibratorservicestests/utils, with fake implementations used in
service tests.

Create a new android_test module VibratorServiceTests for the moved
tests, configured for pre/postsubmit test mappings.

Fix: 290745798
Test: atest VibratorServiceTests
Change-Id: I07cb81f484584cada371a00f2d3e798350ddf8f2