Simple Backup Agent for the call log.

Simple skeleton agent that reads the state of the call log.  Does not
actually do any backup.  It logs what calls it would backup and what
calls it would remove from backup.  A subsequent CL will add the actual
backup/restore of calls.

Change-Id: Id8832c78a9a5aea71022b45c3cef79ca0b54f584
3 files changed