Mixin database upgrade related data is stored in SharedPreferences and this data is not reliable. Key-value tables should be created in the database to store this data.
Contains the following data:
PREF_ATTACHMENT
PREF_ATTACHMENT_LAST
PREF_ATTACHMENT_OFFSET
PREF_FTS4_UPGRADE
PREF_SYNC_FTS4_OFFSET
PREF_BACKUP