Don't use whitespace as an indent indicator

[oliversalzburg]

This is extremely confusing if your editor is not configured to clearly distinguish different sorts of whitespce

Platforms affected

iOS

Motivation and Context

This is just clean code style IMHO

Description

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

[janpio]

Is it common or convention to use tabs in plist files vs spaces?

[oliversalzburg]

@janpio What I understand from comments in the code and from observing XCode output files, it appears to be the default behavior of current XCode versions.