Fix flaky VibrationThreadTest.vibrate_multipleVibrations_withCancel

Update VibrationThreadTest to setup the VibratorController callback
listener mock only once from the setup method, to avoid
UnfinishedStubbingException from tests that dispatches more than one
vibration to the VibrationThread.

Fix: 292106856
Test: VibrationThreadTest
Change-Id: Ice806725c6f9b359c0e73deee250d01a3c267996