fix(ngMockE2E): allow $httpBackend.passThrough() to work when ngMock is loaded

Allow $httpBackend.passThrough() to work normally when ngMock is loaded
concurrently with ngMockE2E, as is typically the case when writing tests with
angular.mock.module()

Fixes #1434
Closes #13124

src/ngMock/angular-mocks.js

@@ -2329,6 +2329,7 @@ angular.module('ngMock', ['ng']).provider({
  * the {@link ngMockE2E.$httpBackend e2e $httpBackend} mock.
  */
 angular.module('ngMockE2E', ['ng']).config(['$provide', function($provide) {
+  $provide.value('$httpBackend', angular.injector(['ng']).get('$httpBackend'));
   $provide.decorator('$httpBackend', angular.mock.e2e.$httpBackendDecorator);
 }]);
 

test/ngMock/angular-mocksSpec.js

@@ -2150,12 +2150,12 @@ describe('ngMockE2E', function() {
     var hb, realHttpBackend, callback;
 
     beforeEach(function() {
-      module(function($provide) {
-        callback = jasmine.createSpy('callback');
+      callback = jasmine.createSpy('callback');
+      angular.module('ng').config(function($provide) {
         realHttpBackend = jasmine.createSpy('real $httpBackend');
         $provide.value('$httpBackend', realHttpBackend);
-        $provide.decorator('$httpBackend', angular.mock.e2e.$httpBackendDecorator);
       });
+      module('ngMockE2E');
       inject(function($injector) {
         hb = $injector.get('$httpBackend');
       });