Add NetworkMonitor constants to SystemApi

NetworkMonitor lives in the NetworkStack which must only use system
APIs. This includes constants used by NetworkMonitor and captive portal
login.

Bug: 112869080
Test: m
Merged-In: I8b5f0bb61c3ef0d2f33af7dd67b72ac6c5a1d1b5
Change-Id: I4879568d3fbf9435767c8d4d0ab5198d421a2f4f
2 files changed
tree: ffd3b1a850daf0b057b4fc4c4e25d96529d3c3b4
  1. core/
  2. services/
  3. tests/