Refactor ResourceManagerTest to make it insensitive to the change of TsFileResource size

[jt2594838]

As the title says.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 39.47%. Comparing base (aa16713) to head (3f46ead).

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #15445      +/-   ##
============================================
+ Coverage     39.46%   39.47%   +0.01%     
  Complexity      198      198              
============================================
  Files          4660     4660              
  Lines        302154   302154              
  Branches      37784    37784              
============================================
+ Hits         119249   119281      +32     
+ Misses       182905   182873      -32     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.