add optional mutation checks for shared informer cache

hack/make-rules/test.sh

@@ -23,6 +23,10 @@ source "${KUBE_ROOT}/hack/lib/init.sh"
 
 kube::golang::setup_env
 
+# start the cache mutation detector by default so that cache mutators will be found
+KUBE_CACHE_MUTATION_DETECTOR="${KUBE_CACHE_MUTATION_DETECTOR:-true}"
+export KUBE_CACHE_MUTATION_DETECTOR
+
 kube::test::find_dirs() {
   (
     cd ${KUBE_ROOT}