Fixes reading on null error for mail notifications

[Godmartinz]

Description

Checks to see if checkedOutTo is not null itself before failing on a locale check for mail notifications.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• [x ] Bug fix (non-breaking change which fixes an issue)

[what-the-diff]

PR Summary

• Improved Safety Measures for null values
  The update ensures when accessing the locale attribute in the onCheckedOut and onCheckedIn methods, it won't cause a crash even if the value is not available (null). This makes the methods more reliable and less prone to errors in uncertain scenarios.