RUMM-3267: Remove mapping file size check

[0xnm]

What does this PR do?

Requests too big will fail with status 413 and message Request too large, so removing mapping file size check from the plugin to rely on the status code instead. Mapping file size limits are mentioned in the docs.

Review checklist (to be filled by reviewers)

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• [ ] Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• [ ] Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Merging #166 (06a2950) into develop (42ed8ea) will decrease coverage by 0.26%. The diff coverage is 100.00%.

@@              Coverage Diff              @@
##             develop     #166      +/-   ##
=============================================
- Coverage      86.90%   86.63%   -0.26%     
+ Complexity       179      177       -2     
=============================================
  Files             21       21              
  Lines            580      576       -4     
  Branches          73       72       -1     
=============================================
- Hits             504      499       -5     
- Misses            48       49       +1     
  Partials          28       28              

Impacted Files	Coverage Δ
.../datadog/gradle/plugin/DdExtensionConfiguration.kt	100.00% <ø> (ø)
...m/datadog/gradle/plugin/internal/OkHttpUploader.kt	84.03% <100.00%> (-0.52%)	:arrow_down:

... and 1 file with indirect coverage changes