test: remove hardcoded app-shell test

With this change we remove the hard coded app-shell test that is currently failing in Node.Js 12.

We can remove this test, because this is a duplicate of https://github.com/angular/angular-cli/blob/master/tests/legacy-cli/e2e/tests/build/build-app-shell-with-schematic.ts which app-shell is generated using schematics.

(cherry picked from commit c95ab70)