Use common states for "Normal" and "Low" in `binary_sensor` (#142465)

* Use common state for "Normal" in `binary_sensor`

Replace the "Normal" string for `battery` and the two references to it from `heat` and `cold` to it with the common state.

* Use common state for "Low" in `binary_sensor`

homeassistant/components/binary_sensor/strings.json

@@ -124,8 +124,8 @@
     "battery": {
       "name": "Battery",
       "state": {
-        "off": "Normal",
-        "on": "Low"
+        "off": "[%key:common::state::normal%]",
+        "on": "[%key:common::state::low%]"
       }
     },
     "battery_charging": {
@@ -145,7 +145,7 @@
     "cold": {
       "name": "Cold",
       "state": {
-        "off": "[%key:component::binary_sensor::entity_component::battery::state::off%]",
+        "off": "[%key:common::state::normal%]",
         "on": "Cold"
       }
     },
@@ -180,7 +180,7 @@
     "heat": {
       "name": "Heat",
       "state": {
-        "off": "[%key:component::binary_sensor::entity_component::battery::state::off%]",
+        "off": "[%key:common::state::normal%]",
         "on": "Hot"
       }
     },