chore(app.scenario): test docs app against production libraries

We have had issues where the docs application has gone down because
our build included invalid URLs to the production angular libraries.

This change runs a subset of the docs e2e tests directly against these
production libraries to ensure that they are accessible. If not then these
tests will fail and the CI build will abort, preventing the docs app from
being updated.

Closes #14769

Author: petebacondarwin

docs/app/e2e/app.scenario.js

@@ -39,7 +39,7 @@ describe('docs.angularjs.org', function () {
 
 
     it('should change the page content when clicking a link to a service', function () {
-      browser.get('build/docs/index.html');
+      browser.get('build/docs/index-production.html');
 
       var ngBindLink = element(by.css('.definition-table td a[href="api/ng/directive/ngClick"]'));
       ngBindLink.click();
@@ -51,33 +51,33 @@ describe('docs.angularjs.org', function () {
 
 
     it('should be resilient to trailing slashes', function() {
-      browser.get('build/docs/index.html#!/api/ng/function/angular.noop/');
+      browser.get('build/docs/index-production.html#!/api/ng/function/angular.noop/');
       var pageBody = element(by.css('h1'));
       expect(pageBody.getText()).toEqual('angular.noop');
     });
 
 
     it('should be resilient to trailing "index"', function() {
-      browser.get('build/docs/index.html#!/api/ng/function/angular.noop/index');
+      browser.get('build/docs/index-production.html#!/api/ng/function/angular.noop/index');
       var pageBody = element(by.css('h1'));
       expect(pageBody.getText()).toEqual('angular.noop');
     });
 
 
     it('should be resilient to trailing "index/"', function() {
-      browser.get('build/docs/index.html#!/api/ng/function/angular.noop/index/');
+      browser.get('build/docs/index-production.html#!/api/ng/function/angular.noop/index/');
       var pageBody = element(by.css('h1'));
       expect(pageBody.getText()).toEqual('angular.noop');
     });
 
 
     it('should display formatted error messages on error doc pages', function() {
-      browser.get('build/docs/index.html#!error/ng/areq?p0=Missing&p1=not%20a%20function,%20got%20undefined');
+      browser.get('build/docs/index-production.html#!error/ng/areq?p0=Missing&p1=not%20a%20function,%20got%20undefined');
       expect(element(by.css('.minerr-errmsg')).getText()).toEqual("Argument 'Missing' is not a function, got undefined");
     });
 
     it("should display an error if the page does not exist", function() {
-      browser.get('build/docs/index.html#!/api/does/not/exist');
+      browser.get('build/docs/index-production.html#!/api/does/not/exist');
       expect(element(by.css('h1')).getText()).toBe('Oops!');
     });