[jaeger-v2] Use environment variables in Kafka config

[mahadzaryab1]

Which problem is this PR solving?

• Resolves [jaeger-v2]: Fix Kafka E2E Test To Use Default Environment Variables #6027

Description of the changes

• Leverages the functionality added in Support default values for configuration environment variables open-telemetry/opentelemetry-collector#5228 to remove the logic for rewriting the config and simply setting an environment variable for the Kafka integration tests.

How was this change tested?

• The change is to an integration test so the CI passing is a good test for this change

Checklist

• I have read https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
• I have signed all commits
• I have added unit tests for the new functionality
• I have run lint and test steps successfully
  • for jaeger: make lint test
  • for jaeger-ui: yarn lint and yarn test

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.92%. Comparing base (be48a84) to head (7be814a).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6028      +/-   ##
==========================================
+ Coverage   96.90%   96.92%   +0.01%     
==========================================
  Files         349      349              
  Lines       16599    16599              
==========================================
+ Hits        16086    16088       +2     
+ Misses        329      328       -1     
+ Partials      184      183       -1     

Flag	Coverage Δ
badger_v1	7.98% <ø> (ø)
badger_v2	1.81% <ø> (ø)
cassandra-4.x-v1	15.75% <ø> (ø)
cassandra-4.x-v2	1.74% <ø> (ø)
cassandra-5.x-v1	15.75% <ø> (ø)
cassandra-5.x-v2	1.74% <ø> (ø)
elasticsearch-6.x-v1	18.69% <ø> (ø)
elasticsearch-7.x-v1	18.75% <ø> (ø)
elasticsearch-8.x-v1	18.94% <ø> (ø)
elasticsearch-8.x-v2	1.80% <ø> (ø)
grpc_v1	9.51% <ø> (ø)
grpc_v2	7.12% <ø> (ø)
kafka-v1	9.69% <ø> (ø)
kafka-v2	1.81% <ø> (ø)
memory_v2	1.81% <ø> (ø)
opensearch-1.x-v1	18.80% <ø> (+0.01%)	⬆️
opensearch-2.x-v1	18.79% <ø> (-0.02%)	⬇️
opensearch-2.x-v2	1.80% <ø> (-0.02%)	⬇️
tailsampling-processor	0.46% <ø> (ø)
unittests	95.71% <ø> (+0.01%)	⬆️

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