Fix migration 201 tests to actually test changes

Previously for migration 201 the indexes dictionary was overwritten
causing the assertIn statement to tests against itself. This patch
fixes it so that the test checks the new indexes are created
correctly against the table and also checks they are removed on
downgrade.

Fixes bug 1226924

Change-Id: Ie518041c6b7d534ed1b96e2f9b4e7206f4b68d87
Merge "Fix migration 201 tests to actually test changes"