agents: run review agents manually

The review agents are broken right now, so don't run them automatically.
They should still be runnable on demand.

Change-Id: I22e5ff46f917a49d0c267a0b1e8c63ae2165347d
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/603461
Reviewed-by: Brian Gan <brgan@google.com>
Commit-Queue: Brian Gan <brgan@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>
Tested-by: Brian Gan <brgan@google.com>

agents/agent_configs.txtpb

@@ -10,7 +10,7 @@ configs {
   include_filters {
     project: "git-repo"
   }
-  automatic: true
+  automatic: false
 }
 
 # Core Internals Agent
@@ -22,5 +22,5 @@ configs {
   include_filters {
     project: "git-repo"
   }
-  automatic: true
+  automatic: false
 }