Delay refreshing after loading the device to prevent extra expand action

The devices in the same set may not all connected immediately after one
device is connected. Add a delay on refreshing to wait both devices be
connected and ready before fetching their initial state.

Flag: EXEMPT bugfix
Bug: 417628947
Test: manually test with real device
Change-Id: I81c82b1a6bab428e872c46ca34428f07a76d1055