API review for storagemonitoring

- Internal implementation of JSON operation all toggled into hidden API.

Bug: 129800875
Test: build
Change-Id: I97b255c4197d85d774b42905cf87bec9c4a9adb7
(cherry picked from commit 85336a80e5c1705854267c6c42208f550a05913a)
5 files changed