Request: Notification_Icon for Buttons

[owenmckeith]

This request is to add the ability to use a MDI icon for the buttons displayed on companion app (and android auto) for notifications.
The example code below would:

• Android: The mdi:alpha-y-circle-outline for the "Yes" button and mdi:alpha-n-circle-outline for the "No" button.
• iPhone: The sfsymbols:checkmark.circle for the "Yes" button and sfsymbols:xmark.circle for the "No" button.

alias: Notification - Ask to Set Home Alarm when everyone leaves the house
action: notify.mobile_myandoidphone
data:
  title: ARM Security System
  message: Do you want to ARM the Security System?
  data:
    timeout: 600
    car_ui: true
    ttl: 0
    priority: high
    channel: security
    notification_icon: mdi:shield-lock-outline
    actions:
      - action: yes-arm
        title: "YES"
        notification_icon: mdi:alpha-y-circle-outline
        icon: "sfsymbols:checkmark.circle"
      - action: no-arm
        title: "NO"
        notification_icon: mdi:alpha-n-circle-outline
        icon: "sfsymbols:xmark.circle"