[api] Adds suffix to percentile metric name

[frankfliu]

Description

Brief description of what this PR is about

• If this change is a backward incompatible change, why must this change be made?
• Interesting edge cases to note here

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.28%. Comparing base (4eb29bd) to head (4dc74ea).
Report is 1 commits behind head on master.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #3011      +/-   ##
============================================
- Coverage     72.30%   72.28%   -0.03%     
+ Complexity     7289     7286       -3     
============================================
  Files           722      722              
  Lines         32491    32494       +3     
  Branches       3390     3390              
============================================
- Hits          23494    23489       -5     
- Misses         7381     7387       +6     
- Partials       1616     1618       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.