Move Ringtone creation onto the AsyncRingtonePlayer thread.

Ringtone initialization on the main thread can cause deadlocks, because
it internally blocks on some asynchronous tasks.

Use the real AsyncRingtonePlayer in the RingerTest.

Bug: 273629038
Test: atest, presubmit
Change-Id: Ifc9f19d0a847fc12e75d795ae7fd3ed3b1729382
4 files changed