Merge "Improve documentation for NetworkCallbacks."
am: c1ea43fa1c

Change-Id: I7384a0224bdf3fe86aee3733d4b7a6e5e12b5a4e
tree: 51c388d901e7258571d2ffcb569c591cb06dcbb9
  1. core/
  2. services/
  3. tests/