Remove device from known_devices upon import in ping device tracker

[jpbede]

Proposed change

If the YAML is imported via the config flow and the device still exists in known_devices.yaml, the config entry will suffix the new entity with _2 as the entity is already used by the device_tracker platform which restores the entities from known_devices.yaml on restart.

This PR solves this problem by delaying the import of the device tracker after the start of the HA and then checking if there is already a state with this entity ID and if the device exists in known_devices.yaml before the import is triggered. If this is the case, the device is deleted from known_devices.yaml and the state machine and the import is triggered.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue:
• This PR is related to issue: Ping yaml entry migration #104915
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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[home-assistant]

Hey there @home-assistant/core, mind taking a look at this pull request as it has been labeled with an integration (device_tracker) you are listed as a code owner for? Thanks!

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[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

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[MartinHjelmare]

Looks good!

[jpbede]

Thanks @MartinHjelmare