Start migration to notedb implementation of PatchSetApprovals
Encapsulate the current state of the migration in a NotesMigration
class. For each database table (or broader group of functionality)
that we migrate to notedb, configure a boolean indicating whether that
data should be read from notes, defaulting to false.
Unlike reads, NotesMigration contains just a single boolean
indicating that data should be written. We don't attempt to write
just some types of data; as the migration continues we will just
rewrite history.
Since most existing reads of the PatchSetApprovals table have been
migrated to ApprovalsUtil, most implementation changes happen there.
There are a few other implementations scattered around, and some that
will require a bit more work (e.g. stamping normalized approvals at
submit time).
Change-Id: I5676267d4de607c385e8c9917a89333863b9c9e7
45 files changed
