Provide more feedback to Settings when sessions fail

This change updates the VPN state when IKEv2 sessions fail, and when
configuration errors occur.

Bug: 162289824
Test: Manual testing with IKEv2/PSK
Change-Id: I2e8c6f421d2898f97b0ac422b2276edf9ef923f1
2 files changed
tree: 57c665b43e855a3b40382bdd7a105dc829e78d7f
  1. core/
  2. services/
  3. tests/