floss: prefer SBC over AAC as default

Floss attempts to open AVDTP channel for the codec with the highest
priority for default. Some controllers have issues when closing a
non-SBC AVDTP channel and immediately opening another for SBC.

This CL sets SBC as the highest priority codec so that does not occur.

Bug: 306542979
Flag: EXEMPT floss-only
Test: m Bluetooth
Change-Id: I3fcde3d71c6a34e02df8f7fa62bf9f42f6df9736