Disable automatic camelCasing in proto JSON

[aaronc]

closes: #6826

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Before we can merge this PR, please make sure that all the following items have been
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• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #6833 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #6833   +/-   ##
=======================================
  Coverage   61.42%   61.42%           
=======================================
  Files         509      509           
  Lines       31457    31457           
=======================================
  Hits        19321    19321           
  Misses      10637    10637           
  Partials     1499     1499