Reland: Add tests for BQR Events

Test sending BQR events and make sure callbacks
are called and the evenet FIFO contains the correct
events.

Bug: 322230000
Test: atest net_test_btif_stack
Flag: EXEMPT, simple bug fix
Change-Id: Ia99e56b9e6019a1637204a7e53fce6579d1810f3