GitLab

CastAudioJson encapsulates the path to tuning config and system config.

The commit also makes CastAudioJson as its own build target so that it
can be used by other components.

Bug: internal b/109845931
Test: Tested on Joplin
Change-Id: I6aef283b94f9ff48c9cadb15db6fbdb73756fbf1
Reviewed-on: https://chromium-review.googlesource.com/1095117
Commit-Queue: Chinyue Chen <chinyue@chromium.org>
Reviewed-by: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567585}