Use NORMAL synchronous mode for WAL journal mode

When synchronous is NORMAL (1), the SQLite database engine will still
sync at the most critical moments, but less often than in FULL mode.

With this change, the number of writes is reduced by 50%,
more than 5x improvement in write performance, read performance is
the same.

Test: Manual + SQLiteDatabaseTest
Bug: 76033286
Change-Id: I13526962bbaeae028a9c6cb668aa9f94bbc2a44d