Fix areacello in BCC-CSM2-MR

[remi-kazeroni]

Description

This PRs applies the OceanFixGrid to the areacello of the BCC-CSM2-MR model. That is needed for ESMValGroup/ESMValTool#3021.

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[codecov]

Codecov Report

Merging #1993 (ca3b31a) into main (c5d23e2) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1993   +/-   ##
=======================================
  Coverage   92.79%   92.79%           
=======================================
  Files         236      236           
  Lines       12437    12438    +1     
=======================================
+ Hits        11541    11542    +1     
  Misses        896      896           

Impacted Files	Coverage Δ
esmvalcore/cmor/_fixes/cmip6/bcc_csm2_mr.py	100.00% <100.00%> (ø)

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[schlunma]

Looks good to me, thanks @remi-kazeroni!

[valeriupredoi]

it do to me too 🍺