Make SQLiteQuery and SQLiteProgram final.

We can do this because the classes already cannot be subclassed
by applications due to the fact they only have package private
constructors.

One very nice consequence of this observation is that we can hide or
delete several @deprecated protected members which are effectively
inaccessible because applications cannot create subclasses!

Change-Id: I2d3a0d2ad72b9289ebcdf907e4e4e6caf27f9076