facebook#13671 Fixing an issue where if the images are coming from iC…

…loud, no filename comes with them and the application crashes

Libraries/CameraRoll/RCTCameraRollManager.m

@@ -199,7 +199,7 @@ static void RCTResolvePromise(RCTPromiseResolveBlock resolve,
               @"group_name": [group valueForProperty:ALAssetsGroupPropertyName],
               @"image": @{
                 @"uri": uri,
-                @"filename" : filename,
+                @"filename" : filename ? filename : @"",
                 @"height": @(dimensions.height),
                 @"width": @(dimensions.width),
                 @"isStored": @YES,