AppRunner: Ping manager once a second

Change-Id: I8c0da7fe77df4b400bf04570fc3c219fc0c00039
diff --git a/apps/app-runner/server.go b/apps/app-runner/server.go
index 51e3db9..44e86fc 100644
--- a/apps/app-runner/server.go
+++ b/apps/app-runner/server.go
@@ -328,7 +328,7 @@
 			defer s.l.Unlock()
 			// TODO(gio): Wait until all logs are sent over to the manager.
 			if !s.stop {
-				time.Sleep(500 * time.Millisecond)
+				time.Sleep(1 * time.Second)
 				s.pingManager()
 			}
 		}()