Dynamically changing a max cache size is clumsy; almost everyone
should set this when they create the cache.
Fix SQLiteDatabase to copy entries into a new cache when the size
is changed. In pratice this will always be immediately after the
SQLiteDatabase is created. Since the cache field is no longer
final, change the guard on the cache field to the SQLiteDatabase
instance itself.
Change-Id: I4e325f06edc551636723568a52770c0982e2d945