Check P2P channel before requesting network info

WifiP2pSettings requests network info from WifiP2pManager whenever it
gets onDeviceInfoAvailable, but sChannel may be null causing an
IllegalArgumentException. Check that sChannel is not null before
requesting network info.

Bug: 289004627
Test: atest WifiP2pSettingsTest
Change-Id: Ied8c3f8a894683d7b8e368e5c52343adb7d05e4b
2 files changed