Update git submodules

* Update plugins/cookbook-plugin from branch 'master'
  - Bump GWT to 2.8.0 final release
    
    Change-Id: Ica57a0c2ebd31ccd39b25870a674cd25e31b49b2
    
  - Add missing dependency on gerrit-acceptance-framework
    
    Change-Id: I8d2ebdad5687230f63c2fcca7c2383f9653e24d6
    
diff --git a/plugins/cookbook-plugin b/plugins/cookbook-plugin
index 6cb2fcd..aa529cb 160000
--- a/plugins/cookbook-plugin
+++ b/plugins/cookbook-plugin
@@ -1 +1 @@
-Subproject commit 6cb2fcdb54d73abf572a5fbb45db644c56f657ce
+Subproject commit aa529cbeba0a498853d75ce3534f94950e1a7a70