MDC operator should manage the mounting of the manifest secret to the dc

What
Move the logic for mounting the manifest secret from the integreatly installer [1] to the mdc operator [2]

Why
when we restore the operator the secret is not mounted because the owner reference of the deployment config doesn't match the uid of the newly created dc so it gets deleted and recreated without this patch. [1]
Also the operator should manage all it's resources
We probably don't want to put this logic inside the integreatly operator

[1] https://github.com/integr8ly/installation/blob/master/roles/mdc/tasks/patch-manifest.yml
[2] https://github.com/aerogear/mobile-developer-console-operator