Revert "Changing GridMigrationTask to use ModelDbController directly"

This reverts commit 9ef41413e0a9b09b3be58ca214a6cdd7051d2794.

Reason for revert: This was the only launcher CL during the time  b/280669657 and 280680602 occurred

Change-Id: Id7107f0935f84908ca87e1ae4c62ab05efe41a24
18 files changed