Websocket persistent notification: hide the "Websocket settings" link after first use

**Is your feature request related to a problem? Please describe.**

The "Websocket settings" link is handy in the notification initially, but is not something one will normally want to change frequently. It quickly becomes irritating for this to take up valuable attention and screen space.

This is part of several suggestions to improve the persistent notification (linked by #2266).

**Describe the solution you'd like**

After the configuration link is used once, it should be replaced by a much more subtle :gear: icon.

**Describe alternatives you've considered, if any**

1. Have it always be a gear icon, even at first.
2. Just never have that link there; people can find and configure it in the app

**Additional context**

As noted, following on from https://github.com/home-assistant/android/issues/2266#issuecomment-1037329212_