test(ngRepeat): fix test setup for ngRepeat stability test

The repeated template contained `{{key}}:{{val}}` but the repeat expression
was `"item in items"`, so `key` and `val` were not actually available.

The tests were passing anyway, since they did not rely upon the actual
text content of the template.

Closes #11761

Author: Nick Anderson

test/ng/directive/ngRepeatSpec.js

@@ -1084,7 +1084,7 @@ describe('ngRepeat', function() {
     beforeEach(function() {
       element = $compile(
         '<ul>' +
-          '<li ng-repeat="item in items">{{key}}:{{val}}|></li>' +
+          '<li ng-repeat="item in items">{{item}}</li>' +
         '</ul>')(scope);
       a = {};
       b = {};