Fix saving index pattern when there is a conflict (#21947)

Author: jen-huang

src/ui/public/index_patterns/__tests__/_index_pattern.test.js

@@ -99,7 +99,9 @@ jest.mock('../../saved_objects', () => {
       update: async (type, id, body, { version }) => {
         if (object._version !== version) {
           throw {
-            statusCode: 409
+            res: {
+              status: 409
+            }
           };
         }
 
@@ -158,6 +160,6 @@ describe('IndexPattern', () => {
       result = err;
     }
 
-    expect(result.statusCode).toBe(409);
+    expect(result.res.status).toBe(409);
   });
 });

src/ui/public/index_patterns/_index_pattern.js

@@ -463,7 +463,7 @@ export function IndexPatternProvider(Private, config, Promise, confirmModalPromi
           setVersion(this, _version);
         })
         .catch(err => {
-          if (err.statusCode === 409 && saveAttempts++ < MAX_ATTEMPTS_TO_RESOLVE_CONFLICTS) {
+          if (_.get(err, 'res.status') === 409 && saveAttempts++ < MAX_ATTEMPTS_TO_RESOLVE_CONFLICTS) {
             const samePattern = new IndexPattern(this.id);
             return samePattern.init()
               .then(() => {