Update Zuul layout to support multiple reporters

Change-Id: Ib3f72b45116bb5458d0dea2a891471b74be9eb2f

modules/openstack_project/files/zuul/layout.yaml

@@ -13,8 +13,10 @@ pipelines:
         - event: comment-added
           comment_filter: (?i)^\s*recheck(( (?:bug|lp)[\s#:]*(\d+))|( no bug))\s*$
     success:
+      gerrit:
         verified: 1
     failure:
+      gerrit:
         verified: -1
 
   - name: gate
@@ -30,11 +32,14 @@ pipelines:
         - event: comment-added
           comment_filter: (?i)^\s*reverify(( (?:bug|lp)[\s#:]*(\d+))|( no bug))\s*$
     start:
+      gerrit:
         verified: 0
     success:
+      gerrit:
         verified: 2
         submit: true
     failure:
+      gerrit:
         verified: -2
 
   - name: post
@@ -82,8 +87,10 @@ pipelines:
         - event: comment-added
           comment_filter: (?i)^\s*check experimental\s*$
     success:
+      gerrit:
         force-message: true
     failure:
+      gerrit:
         force-message: true
 
   - name: periodic