core/homeassistant/components/alarmdecoder/icons.json

{
  "entity": {
    "sensor": {
      "alarm_panel_display": {
        "default": "mdi:alarm-check"
      }
    }
  },
  "services": {
    "alarm_keypress": "mdi:dialpad",
    "alarm_toggle_chime": "mdi:abc"
  }
}