Switch wifi to 4g don't work sometimes

[leoagle]

1. two android client join same room on wifi, publish and subscribe
2. switch one client from wifi to 4g, another one keep wifi
3. sometimes both of them have remote and local stream after network changed. sometimes, the switch one show up "ICE connection failed" log, then the another one remote video stopped.

BTW, I use 4.3.1 sdk, and set continualGatheringPolicy equal GATHER_CONTINUALLY.