Fixing up repo for stable/icehouse branch

* Adding defaultbranch to .gitreview
* Removing Berksfile.lock from .gitreview
* Removing Gemfile.lock from .gitignore
* Adding updated Berksfile.lock file
* Adding updated Gemlock.lock file

Partial-Bug: 1349150
Change-Id: I7ad4a83b26d7e5845f0548e8c5004bce1ac2b417