Fix iCloud device battery level can be None

[Quentame]

Proposed change

Fix this error :

   File "/usr/src/homeassistant/homeassistant/components/icloud/__init__.py", line 514, in update
     self._battery_level = int(self._status.get(DEVICE_BATTERY_LEVEL, 0) * 100)
 TypeError: unsupported operand type(s) for *: 'NoneType' and 'int'

It appears that a retrieved device can have a battery status not "Unknown" with a battery level to None on the API side, maybe the Apple Watch (which I can't test on).

So just checking the None value before setting a battery level.

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)
• 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: fixes Error setting up iCloud #31152
• This PR is related to issue:
• Link to documentation pull request:

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