* Add simple sanity checks to scanned accounts, skip over if bad
* Fix existing unit tests and add new unit test for this change
* Also fixed minor bug in EmailContent that was never triggered in
production code (only discovered it via a unit test).
* Also fixed minor bug in an existing unit test
Bug: 2937595
Change-Id: Id60bbb5d8bd923db043d46891c7f89d7debb0a11