RUMM-2380: Enable custom application version support

[0xnm]

What does this PR do?

Cherry picks #1020 into 1.14.0 release branch.

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 #1026 (b8fb0e3) into release/1.14.0 (26195cd) will increase coverage by 0.10%.
The diff coverage is 96.49%.

@@                Coverage Diff                 @@
##           release/1.14.0    #1026      +/-   ##
==================================================
+ Coverage           83.03%   83.12%   +0.10%     
==================================================
  Files                 270      272       +2     
  Lines                9249     9268      +19     
  Branches             1488     1490       +2     
==================================================
+ Hits                 7679     7704      +25     
+ Misses               1157     1156       -1     
+ Partials              413      408       -5     

Impacted Files	Coverage Δ
...oid/core/internal/system/NoOpAppVersionProvider.kt	66.67% <66.67%> (ø)
...n/com/datadog/android/core/internal/CoreFeature.kt	91.56% <87.50%> (+0.04%)	⬆️
...oid/src/main/kotlin/com/datadog/android/Datadog.kt	81.97% <100.00%> (+0.45%)	⬆️
.../main/kotlin/com/datadog/android/_InternalProxy.kt	87.50% <100.00%> (-1.39%)	⬇️
.../core/internal/system/DefaultAppVersionProvider.kt	100.00% <100.00%> (ø)
...adog/android/error/internal/CrashReportsFeature.kt	100.00% <100.00%> (ø)
.../src/main/kotlin/com/datadog/android/log/Logger.kt	95.97% <100.00%> (ø)
...atadog/android/log/internal/domain/LogGenerator.kt	99.02% <100.00%> (+0.02%)	⬆️
...otlin/com/datadog/android/rum/_RumInternalProxy.kt	100.00% <100.00%> (ø)
...lin/com/datadog/android/rum/internal/RumFeature.kt	93.00% <100.00%> (+0.07%)	⬆️
... and 16 more