Use opencensus metric package for process metrics

[bogdandrutu]

Signed-off-by: Bogdan Drutu bogdandrutu@gmail.com

[codecov]

Codecov Report

Merging #5486 (7f5cfea) into main (f1ba384) will decrease coverage by 0.07%.
The diff coverage is 73.10%.

@@            Coverage Diff             @@
##             main    #5486      +/-   ##
==========================================
- Coverage   90.84%   90.76%   -0.08%     
==========================================
  Files         192      192              
  Lines       11420    11479      +59     
==========================================
+ Hits        10374    10419      +45     
- Misses        824      831       +7     
- Partials      222      229       +7     

Impacted Files	Coverage Δ
service/internal/telemetry/process_telemetry.go	71.55% <72.97%> (-1.67%)	⬇️
service/telemetry.go	77.24% <75.00%> (-0.16%)	⬇️
pdata/internal/common.go	95.38% <0.00%> (+0.76%)	⬆️

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[codeboten]

Overall this looks great, just a nit regarding a variable name.