Add comments to frozen netd AIDL API files

Generated by re-freezing the API with the new aidl_interface code, and
replacing the previous API with the new files. This only adds comments.

Test: comments only, builds
Bug: 134452637
Merged-In: I101ffee4045592d51417d3c954c54b2edfdd332d
(cherry picked from commit f6ff9b4068f96f5db0ac900f1a4ee8fa92736d9a)

Change-Id: I67eeb159696edf596dd937f6e630e91bfb6821ce