Wait for SCO connected signal to ring when BT is connected

Wait for SCO connected signal in AsyncRingtonePlayer before
starting to play the ringtone when a BT device is connected. This
reduces "broken" sounding ringtones when BT is connected.

This change also changes how AsyncRingtonePlayer#isPlaying works
because delays in PLAY could cause multiple PLAY commands to stack.

Bug: 274081739
Test: Test: manual testing; atest TelecomUnitTests; atest CtsTelecomTestCases
Change-Id: If9bb02166756b17282e830061f24365550ca8978