Tile cache files stored in same location as DSA data

[kerryrobinson]

In the latest version of DSA built for Android, I am seeing that tilecache pngs are put in that files folder, which show up when browsing for operational data (I think we had purposely made the Add Data tool look both in OperationalData and the base directly. One way to get around this would probably be to create a DSA folder under files, which then had the DsaAppConfig.json and data folders in it. But again, it is still frustrating to have to use Android Studio to manage that folder.

Note, this will become moot once we are able to store the DSA data files in a different location than the internal app sandbox area (see #372).