aaudio: do error callback if thread registration fails

This can prevent a silent disconnect caused by a disconnect
happening right when the stream is started.

These mods were suggested by MediaTek.

Bug: 357011642
Test: atest AAudioTests
Test: OboeTester TEST DISCONNECT
Flag: EXEMPT bugfix
Change-Id: I754ad7d046fa932ed928ef54df8f9dfaa7b753c0