Fix flaky WireframeUtils test

[0xnm]

What does this PR do?

This change fixes flaky M return false W checkIsValidWireframe(){ covered by another with solid background } test.

Test was failing because there was a possibility to generate wireframe without background color, so it has isOpaque == false.

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 #1208 (a995ec2) into feature/sdkv2 (932cecb) will increase coverage by 0.00%.
The diff coverage is n/a.

@@              Coverage Diff               @@
##           feature/sdkv2    #1208   +/-   ##
==============================================
  Coverage          82.59%   82.59%           
==============================================
  Files                351      351           
  Lines              12480    12475    -5     
  Branches            2058     2056    -2     
==============================================
- Hits               10307    10303    -4     
- Misses              1533     1535    +2     
+ Partials             640      637    -3     

Impacted Files	Coverage Δ
...src/main/kotlin/com/datadog/android/DatadogSite.kt	83.33% <0.00%> (-3.33%)	⬇️
...ain/java/com/datadog/opentracing/PendingTrace.java	57.76% <0.00%> (-1.72%)	⬇️
...in/com/datadog/android/log/internal/LogsFeature.kt	84.16% <0.00%> (-0.99%)	⬇️
.../android/rum/internal/monitor/DatadogRumMonitor.kt	90.81% <0.00%> (-0.54%)	⬇️
...rc/main/java/com/datadog/opentracing/DDTracer.java	56.07% <0.00%> (-0.42%)	⬇️
.../android/rum/internal/domain/scope/RumViewScope.kt	95.18% <0.00%> (-0.18%)	⬇️
...lin/com/datadog/android/rum/internal/RumFeature.kt	92.03% <0.00%> (ø)
...android/log/internal/logger/TelemetryLogHandler.kt	85.71% <0.00%> (ø)
...android/v2/core/internal/net/DataOkHttpUploader.kt	94.37% <0.00%> (ø)
...ndroid/telemetry/internal/TelemetryEventHandler.kt	72.80% <0.00%> (ø)
... and 4 more

[mariusc83]

I think I fixed this also in my current PR