Revert "Update mysql-connector-java to 6.0.6"

This reverts commit 051ca83af772401af317e2e84053c71a5b7527ea.

Updating to mysql-connector-java 6.0.6 broke the sql upgrader in Gerrit.

Bug: Issue 7331
Change-Id: Id6dc6c93b6f989b096114a35c84cb4febae07613
2 files changed