[Packman] [2D Animation] Adding staging package registry will create "Package cannot be found" errors on install

After opening the editor, if the user adds the staging package registry to their package manifest, if they attempt to install the 2D Animation 3.0.3 via the Package Manager, the following error will be thrown and installation will fail:

Unable to add package [com.unity.2d.animation@3.0.3]: Package [com.unity.3d.animation@3.0.3] cannot be found

It is unsure whether this issue is with the Package Manager or the package itself.

Steps to reproduce:
1) Create a new 19.3 project
2) With the project open, add the staging registry to the manifest.json by adding the line following the before the last closing brace:
, "registry": "https://staging-packages.unity.com"
3) Return to the editor and open Package Manager
4) Attempt to install 2D Animation 3.0.3
5) Observe installation error