Update widgets_binding_observer.dart

[abdelrahmanelmarakby]

fix widgets_binding_observer.dart:183:17: Error: A non-null value must be returned since the return type 'String' doesn't allow null. because switch returns String? not String because there is no default case

📜 Description

💡 Motivation and Context

💚 How did you test it?

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps

[ueman]

Apparently, there were more states added: https://master-api.flutter.dev/flutter/dart-ui/AppLifecycleState.html

[marandaneto]

Makes sense @abdelrahmanelmarakby
Would you mind adding a changelog entry?

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: +2.70 🎉

Comparison is base (7e30648) 88.65% compared to head (fc43e6f) 91.35%.

❗ Current head fc43e6f differs from pull request most recent head 76d9af1. Consider uploading reports for the commit 76d9af1 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1503      +/-   ##
==========================================
+ Coverage   88.65%   91.35%   +2.70%     
==========================================
  Files         142      161      +19     
  Lines        4389     5150     +761     
==========================================
+ Hits         3891     4705     +814     
+ Misses        498      445      -53     

Impacted Files	Coverage Δ
flutter/lib/src/widgets_binding_observer.dart	98.11% <100.00%> (ø)

... and 60 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[abdelrahmanelmarakby]

@marandaneto will add the entry , any thing else to take in consideration?

[marandaneto]

@abdelrahmanelmarakby thanks for the PR.
I will close this one in favor of #1506 because there are more places doing this and can break in the future, so I decided to fix the other cases as well in a single PR.
Will add the credits to the PR tho :)