cmd/coordinator: watch gitmirror pods by prefix, not exact match

I want to spin up a second gitmirror deployment, and we still want it
monitored.

Change-Id: I9701c775aafae31de56a7d3e948bdb56508bb2af
Reviewed-on: https://go-review.googlesource.com/c/build/+/330370
Trust: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
diff --git a/cmd/coordinator/status.go b/cmd/coordinator/status.go
index 9d51e96..6f012f0 100644
--- a/cmd/coordinator/status.go
+++ b/cmd/coordinator/status.go
@@ -207,7 +207,7 @@
 	}
 	var runningGitMirror []api.Pod
 	for _, p := range pods {
-		if p.Labels["app"] != "gitmirror" || p.Status.Phase != "Running" {
+		if !strings.HasPrefix(p.Labels["app"], "gitmirror") || p.Status.Phase != "Running" {
 			continue
 		}
 		runningGitMirror = append(runningGitMirror, p)