fix(sdk-metrics): fix duplicated registration of metrics for collectors

[legendecas]

Which problem is this PR solving?

Fixes #3472

Short description of the changes

• Fixes that MetricStorageRegistry.findOrUpdateCompatibleCollectorStorage always returns undefined, which leads to duplicated registration of metric storage for a collector.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Verified that MetricStorageRegistry.findOrUpdateCompatibleCollectorStorage returns the expected value.

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added

[codecov]

Codecov Report

Merging #3488 (c54ba3b) into main (93222fc) will not change coverage.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3488   +/-   ##
=======================================
  Coverage   93.78%   93.78%           
=======================================
  Files         249      249           
  Lines        7610     7610           
  Branches     1587     1587           
=======================================
  Hits         7137     7137           
  Misses        473      473           

Impacted Files	Coverage Δ
...ges/sdk-metrics/src/state/MetricStorageRegistry.ts	96.49% <100.00%> (+1.75%)	⬆️
...emetry-core/src/platform/node/RandomIdGenerator.ts	87.50% <0.00%> (-6.25%)	⬇️

[dyladan]

Simpler than expected fix