The main motivation is to wrap the bucket DB and metainfo DB, so we
could check if a bucket is empty before applying geofencing config.
Change-Id: I8bac21555e01d51a663fb557bc1acfc8106bc2e1
Testing interfaces is slightly clearer when it's in the package needing
the database rather than each individual implementation.
Change-Id: I10334c214a205f7e510b939b4359a2214c4e060a
