cloudbuild.yaml also needs a top level timeout.

Bug: skia:
Change-Id: Idab02c36778feab40bf6750646929d037db7321a
Reviewed-on: https://skia-review.googlesource.com/139168
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Joe Gregorio <jcgregorio@google.com>
diff --git a/docker/cloudbuild.yaml b/docker/cloudbuild.yaml
index 6cec545..4735da1 100644
--- a/docker/cloudbuild.yaml
+++ b/docker/cloudbuild.yaml
@@ -26,3 +26,4 @@
 images:
   - 'gcr.io/$PROJECT_ID/fiddler:$COMMIT_SHA'
   - 'gcr.io/$PROJECT_ID/skia-release:prod'
+timeout: 7200s