Ensuring endpointslice controller starts up as part of cluster up when all alpha feature gates are enabled

cluster/gce/util.sh

@@ -1283,6 +1283,11 @@ EOF
   if [ -n "${FEATURE_GATES:-}" ]; then
     cat >>$file <<EOF
 FEATURE_GATES: $(yaml-quote ${FEATURE_GATES})
+EOF
+  fi
+  if [ -n "${RUN_CONTROLLERS:-}" ]; then
+    cat >>$file <<EOF
+RUN_CONTROLLERS: $(yaml-quote ${RUN_CONTROLLERS})
 EOF
   fi
   if [ -n "${PROVIDER_VARS:-}" ]; then