Automated code generation reverts some of migration

[bcoe]

@sofisl @billyjacobson the following PR shows that our automated code generation reverts a couple of the changes made to move us away from using the master branch name.

The GitHub action should be easy to fix, we can just update the templates to use the $default-branch variable, and it should work across the board.

Perhaps we could introduce similar functionality to our templates, and do the same thing?