fix: rename groupProperties to groups for capture methods

[marandaneto]

💡 Motivation and Context

Fix found by #129

It's a breaking change but also a fix so not worth raising a major.
We didn't mention it in the docs either, it's just the name of the property and its type.
I'll change it in iOS as well.

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.