recording: fix registering the ViewTreeObserver when its not attached yet

[marandaneto]

:bulb: Motivation and Context

sometimes the SDK inits so early that the view isn't attached yet.

:green_heart: How did you test it?

running and debugging before view is attached

:pencil: Checklist

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