feat: improve android selection gesture

[LucasXu0]

• Extend the gesture hit test area.
• Adjust the Android-style drag handle.
• Fix the issue of "unable to drag the handle from the vertical direction."

android_gesture.mp4

[codecov]

Codecov Report

Attention: 251 lines in your changes are missing coverage. Please review.

Comparison is base (de94a58) 78.13% compared to head (967bac6) 77.16%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
.../src/render/selection/mobile_selection_handle.dart	9.40%	183 Missing ⚠️
...nt/service/selection/mobile_selection_service.dart	25.33%	56 Missing ⚠️
...t/service/selection/desktop_selection_service.dart	0.00%	6 Missing ⚠️
...or_component/service/selection_service_widget.dart	0.00%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #647      +/-   ##
==========================================
- Coverage   78.13%   77.16%   -0.97%     
==========================================
  Files         291      291              
  Lines       12763    12931     +168     
==========================================
+ Hits         9972     9978       +6     
- Misses       2791     2953     +162     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.