Support for writing queries in the VersionedAccountQueries is a
preparatory step before adding support for managing user queries in
the account API.
Implement the onSave method which writes the contents of the current
query list to the queries file, and add a new method to set the query
list from text.
Modify AbstractQueryChangesTest#userQuery to use the new functionality
to set the test queries, thus implicitly adding test coverage of it.
AbstractQueryChangesTest is not the appropriate place to fully test
this functionality, so we don't test the handling of invalid input and
other uses cases. This will be added when we later extend the account
API.
Change-Id: I5bca1bae6b0b7cf295a4ce9591d452a4ded3e5ee
6f51a30a1b