Always update unit of measurement of the utility_meter on state change

[dgomes]

Breaking change

Proposed change

When the utility_meter is initially added and the source for some reason does not have a unit_of_measurement, the utility_meter would never get a unit itself.

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)
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Additional information

• This PR fixes or closes issue: fixes Utility Meter (hourly reset) not showing unit_of_measurement #95406
• This PR is related to issue:
• Link to documentation pull request:

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[janiversen]

LGTM, thanks.

[bdraco]

Its a bit iffy to change the UOM at run time since I don't think we account for it everywhere. There may be side effects we didn't think about in downstream code. It looks like sensor at least tries to handle this though so let's do it and fix anything downstream if needed as I don't see another way with this type of integration / wrapper.