Run the jaeger-agent as a non-root user by default

[chgl]

Which problem is this PR solving?

• Resolves Run the jaeger-agent as a non-root user by default #2460

Short description of the changes

• Added a UID arg, defaulting to 10001, which the build image is running as by default.

[codecov]

Codecov Report

Merging #2466 into master will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2466   +/-   ##
=======================================
  Coverage   95.51%   95.52%           
=======================================
  Files         208      208           
  Lines       10750    10750           
=======================================
+ Hits        10268    10269    +1     
  Misses        406      406           
+ Partials       76       75    -1     

Impacted Files	Coverage Δ
cmd/query/app/server.go	89.14% <0.00%> (-1.56%)	⬇️
plugin/storage/integration/integration.go	80.38% <0.00%> (-0.48%)	⬇️
plugin/storage/badger/spanstore/reader.go	96.79% <0.00%> (+0.64%)	⬆️
cmd/query/app/static_handler.go	85.83% <0.00%> (+1.66%)	⬆️

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[jpkrohling]

crossdock and unit tests CI jobs restarted.

[jpkrohling]

CI looks good. @chgl, could you please rebase this? Once it's done, I'll merge this one.

[jpkrohling]

crossdock-otel job restarted

[jpkrohling]

Thanks!