Adds two new helper functions that can be used when unit testing Angular services
that depend upon upgraded AngularJS services, or vice versa.
The functions return a module (AngularJS or NgModule) that is configured to wire up
the Angular and AngularJS injectors without the need to actually bootstrap a full
hybrid application.
This makes it simpler and faster to unit test services.
PR Close#16848
Currently our plan is to skip the publish, docgen, and update steps for this package.
During RC, we'll determine if the breaking change is too difficult for users, in which case we might restore the package for another major.
PR Close#29550
This PR was merged without API docs and general rollout plan.
We can't release this as is in 5.1 without a plan for documentation, cli integration, etc.
This is to tidy up the `author-packagse`, which currently duplicates a
lot of the configuration in the main packages. We need to
DRY this up so that we don't fall foul of a change in one being missed in
the other.
