Add translation for absolute_humidity device class to template (home-assistant#149814)

Author: NoRi2909

homeassistant/components/template/strings.json

@@ -901,6 +901,7 @@
     },
     "sensor_device_class": {
       "options": {
+        "absolute_humidity": "[%key:component::sensor::entity_component::absolute_humidity::name%]",
         "apparent_power": "[%key:component::sensor::entity_component::apparent_power::name%]",
         "aqi": "[%key:component::sensor::entity_component::aqi::name%]",
         "area": "[%key:component::sensor::entity_component::area::name%]",