[js] fixed issue with StorageTask.then/.catch

lib/modules/storage/index.js

@@ -101,11 +101,11 @@ export const statics = {
     STATE_CHANGED: 'state_changed',
   },
   TaskState: {
-    RUNNING: 'RUNNING',
-    PAUSED: 'PAUSED',
-    SUCCESS: 'SUCCESS',
-    CANCELED: 'CANCELED',
-    ERROR: 'ERROR',
+    RUNNING: 'running',
+    PAUSED: 'paused',
+    SUCCESS: 'success',
+    CANCELLED: 'cancelled',
+    ERROR: 'error',
   },
   Native: {
     MAIN_BUNDLE_PATH: FirebaseStorage.MAIN_BUNDLE_PATH,

lib/modules/storage/task.js

@@ -13,8 +13,8 @@ export default class StorageTask {
     this.path = storageRef.path;
 
     // 'proxy' original promise
-    this.then = promise.then;
-    this.catch = promise.catch;
+    this.then = promise.then.bind(promise);
+    this.catch = promise.catch.bind(promise);
   }
 
   /**