doc: Noted android quirks on serial property

[breautek]

Platforms affected

Docs

Motivation and Context

Closes #111

Description

Added notes on the serial property for android and why it now returns UNKNOWN.

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[breautek]

Initial version of this PR had marked quirks on uuid property, but the actual property in question is actually serial. I was confused with the two properties. uuid property should still be usable. The serial property will always return UNKNOWN now, unless if the application have special privileged permissions, only available to phone manufacturers and/or carriers.

I've since changed and corrected this PR to reflect that.

[breautek]

Corrected the grammar error, thanks for the reviews!