fix: checking is mounted before updating the value of PropertyValueNotifier(#977)

[asjqkkkk]

Fix issue #977

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 72.15%. Comparing base (c6909a7) to head (a3fcf55).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
...nt/service/selection/mobile_selection_service.dart	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #997   +/-   ##
=======================================
  Coverage   72.15%   72.15%           
=======================================
  Files         319      319           
  Lines       15239    15239           
=======================================
  Hits        10996    10996           
  Misses       4243     4243           

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