add branch config support

cros_repoinit.sh

@@ -9,6 +9,11 @@ if [ ${_working_dir_name: -1} = " " ]; then
     _working_dir_name=${_working_dir_name::-1}
 fi
 
+if [ -z "$2" ]
+  then
+    echo "INFO: copy local manifests, No branch specified"
+fi
+
 _mydir="$(pwd)"
 _parentdir="$(dirname "$_mydir")"
 _working_full_path="${_parentdir}/${_working_dir_name}"