This is just a copy of the lineage-19.1 branch of system/bt/.
HEAD revision at the point of copying:
1df53e8efc293f959bdf3e352647f1d56125050d
Merge tag 'android-12.1.0_r11' into staging/lineage-19.1_merge-android-12.1.0_r11
Change-Id: Ic53eb59b25b8b367cb1cdfb27c29c08411c75bce