[SettingsState] fix boot loop due to corrupted database file

Use an explicit fallback file for each settings file. If the original file
is corrupted and fails to be parsed, use the fallback file instead.

The fallback files are updated once daily if the original files are
changed.

BUG: 119723324
Test: manual by pushing a malformed xml file
Change-Id: I1deb203cd1f53649a5675ad90290075fce6ca942