Fix DatabaseMigrations in DatabaseManagerTest

This CL is a little overloaded but does the following:
1. Migration Assert to Truth: Assert.assertThat
2. In every test, for every new column that gets added, it must be added to the `ContentValues device;` for the next version with its default value before `db.insert`
3. Add missing migration of 110->111
4. Fix a few Blog / Int expectations
5. Introduce `assertColumnStringData` for reading and checking string data

Bug: 394969379
Test: atest DatabaseManagerTest
Flag: TEST_ONLY
Change-Id: Ia23ccf1928a63de8ba2906711a45ddb6ffead65d