Add additional wait for galera get synced

- After killing mysql and starting mysql daemon again
we need to wait until Galera is synced because if it's
not synced and we kill mysql on next controller
Galera will lose its quorum

Change-Id: I0d11c23f20a97623efcd670fb499e2a435f44470
Closes-Bug: #1400380
(cherry picked from commit 87359485d88e857aead80d57841b86bd59fa7d12)