Use InterfaceRegistry as AnyResolver for grpc-gateway

[aaronc]

#7540 introduced AnyResolver to InterfaceRegistry so that ServiceMsgs can properly be encoded as in proto JSON. This makes sure that is wired up with grpc-gateway for REST and CLI users decoding ServiceMsg tx's. Marking as a backport.

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[codecov]

Codecov Report

Merging #7646 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #7646   +/-   ##
=======================================
  Coverage   54.15%   54.15%           
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  Files         611      611           
  Lines       38556    38556           
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  Hits        20881    20881           
  Misses      15543    15543           
  Partials     2132     2132