[ci skip] Translation update

homeassistant/components/volvooncall/translations/ja.json

@@ -15,6 +15,7 @@
                     "password": "\u30d1\u30b9\u30ef\u30fc\u30c9",
                     "region": "\u30ea\u30fc\u30b8\u30e7\u30f3",
                     "scandinavian_miles": "\u30b9\u30ab\u30f3\u30b8\u30ca\u30d3\u30a2\u30de\u30a4\u30eb(Scandinavian Miles)\u3092\u4f7f\u7528\u3059\u308b",
+                    "unit_system": "\u5358\u4f4d\u30b7\u30b9\u30c6\u30e0",
                     "username": "\u30e6\u30fc\u30b6\u30fc\u540d"
                 }
             }