Metadata database now creates a new entry on acl connection events,

updates last_active_time on a2dp, hfp, or hearing aid active device
changes, and exposes new function to get most recently connected devices
ordered by last_active_time

Bug: 130984590
Test: atest DatabaseManagerTest
Change-Id: Ifd390d0e270e2f0f94e7c54d26da7aa4bafa651d