Use type-deducing IPC helpers in cma_param_traits.cc
Use type-deducing IPC helpers in cma_param_traits.cc

This is simpler and easier to maintain than manually specifying the
template specialization to use.

BUG=504205

Review URL: https://codereview.chromium.org/1214783004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#336814}

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