Remove current_adapter? from test_sanitize_sql_hash_handles_associations

Because of each adapter implementation differences,
`expected_value` string needed to be handled by each adapter.
This commit removes current_adapter
by using ActiveRecord::ConnectionAdapters::Quoting methods.
Merge pull request #10521 from yahonda/sanitize_oracle

Remove current_adapter? from test_sanitize_sql_hash_handles_associations