Rely on DefaultResource's Service.Name for Exporters

[Austin-Tan]

Follow up to #1744.

Changes

Previous PR #1744 changed Default Resource to comply by spec's service.name requirement. This PR will apply this to all applicable exporters.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Design discussion issue #
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #1768 (88846d0) into main (7d8c403) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1768      +/-   ##
==========================================
+ Coverage   84.16%   84.19%   +0.02%     
==========================================
  Files         187      187              
  Lines        5931     5934       +3     
==========================================
+ Hits         4992     4996       +4     
+ Misses        939      938       -1     

Impacted Files	Coverage Δ
...Telemetry.Exporter.Zipkin/ZipkinExporterOptions.cs	100.00% <ø> (ø)
...rc/OpenTelemetry.Exporter.Jaeger/JaegerExporter.cs	85.00% <100.00%> (+1.66%)	⬆️
...rc/OpenTelemetry.Exporter.Zipkin/ZipkinExporter.cs	87.64% <100.00%> (+0.14%)	⬆️
src/OpenTelemetry/ProviderExtensions.cs	75.00% <100.00%> (+8.33%)	⬆️

[CodeBlanch]

LGTM