core/homeassistant/components/unifiprotect/icons.json

{
  "services": {
    "add_doorbell_text": "mdi:message-plus",
    "remove_doorbell_text": "mdi:message-minus",
    "set_default_doorbell_text": "mdi:message-processing",
    "set_chime_paired_doorbells": "mdi:bell-cog"
  }
}