Fix race condition for dynamic audio buffer capabilities

When getting the dynamic audio buffer capabilities at
btif_enable_bluetooth_evt(), the HCI event of dynamic audio buffer
from the Controller may not be received yet. Move it to
btif_get_adapter_property().

Bug: 178679411
Test: Run dynamic audio buffer test
Change-Id: I93540915bc21675f8719362ec8577aff1aef8d0a