Add missing visibility keywords to all LoadBalancer methods

Quite a few methods are unused, at least in my code base (which does
not cover all extensions). I made them public. All other decisions
are based on the usage of that method in my code base. If you think
a specific method should be public, please tell me.

Change-Id: Ie83a2921fe02a198bd75c5ff7a41bcd4f0b4980b
Merge "Add missing visibility keywords to all LoadBalancer methods"