fix(v4-policy): add missing bucket field

[jkwlui]

fixes #1164

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (conformance-test-bucket@ea48df3). Click here to learn what that means.
The diff coverage is n/a.

@@                    Coverage Diff                     @@
##             conformance-test-bucket    #1168   +/-   ##
==========================================================
  Coverage                           ?   99.19%           
==========================================================
  Files                              ?       12           
  Lines                              ?    11456           
  Branches                           ?      525           
==========================================================
  Hits                               ?    11364           
  Misses                             ?       92           
  Partials                           ?        0           

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