Fix bug in getFileInChangeEdit

Due to a recent refactor, getFileInChangeEdit's return value object
structure changed to not include res.ok. This change adds that back in.

Bug: Issue 4437
Change-Id: I90d20b166dcd0da22da7fe3653342e43a459f81a

polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js

diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js
index 6c052ae..5118d70 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js
@@ -1344,7 +1344,7 @@
             // X-FYI-Content-Type header of the response.
             const type = res.headers.get('X-FYI-Content-Type');
             return this.getResponseObject(res).then(content => {
-              return {content, type};
+              return {content, type, ok: true};
             });
           });
     },

polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html

diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html
index bf238af..6542bb6 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html
@@ -1199,7 +1199,8 @@
           .returns(Promise.resolve('new content'));
 
       return element.getFileInChangeEdit('1', 'test/path').then(res => {
-        assert.deepEqual(res, {content: 'new content', type: 'text/java'});
+        assert.deepEqual(res,
+            {content: 'new content', type: 'text/java', ok: true});
       });
     });
   });