Cleanup released sqlite flags

Remove the simple_sql_comment_scanner flag and any code that is
subsequently unreachable.  A few comments have been updated.

Remove the sqlite_allow_temp_tables flag.  Comments have been updated
to remove references to the flagging.

Flag: EXEMPT flag-cleanup
Test: atest
 * FrameworksCoreTests:android.database
 * CtsDatabaseTestCases
Bug: 347726805
Bug: 347725835
Change-Id: I56969e85e780c924a98700875253dd898452a608