Prepare 2.9.2 release (#513)

diff --git a/pubspec.yaml b/pubspec.yaml
index 5e12d43..9c00f0e 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,7 +1,7 @@
 name: gallery
 description: A resource to help developers evaluate and use Flutter.
 repository: https://github.com/flutter/gallery
-version: 2.9.1+020901
+version: 2.9.2+020902
 
 environment:
   flutter: ^2.2.0