as storage location.
The backup backoff time is not reliable for this as the system still
attempts to backup the magic @pm@ package without checking for the
backoff value.
This is needed to reliably identify USB mass storage devices.
If someone has several identical thumb drives,
this prevents a backup from being performed when non-backup drives get attached.
* With the upcoming changes, and the increasing number of external
libraries being used, plus the usage of Kotlin, it's getting harder
and harder to build this with the AOSP build system.
* It's best to leverage the existing gradle build system instead,
and use the apk that builds.
* Add a script which downloads the apk matching the tag if a tag is
checked out, otherwise downloads the latest.
