RUM-2104: Fix the issue of missing cpu/memory info with RUM view events

[0xnm]

What does this PR do?

RUM data was missing cpu/memory info since SDK v2, because we were safe-casting the property of RUM context to the wrong type.

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 #1693 (022c8f7) into develop (b6112d9) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #1693      +/-   ##
===========================================
- Coverage    83.70%   83.69%   -0.01%     
===========================================
  Files          463      463              
  Lines        15889    15887       -2     
  Branches      2371     2369       -2     
===========================================
- Hits         13299    13296       -3     
- Misses        1947     1959      +12     
+ Partials       643      632      -11     

Files	Coverage Δ
...android/rum/internal/vitals/VitalReaderRunnable.kt	100.00% <100.00%> (ø)

... and 21 files with indirect coverage changes