Process other two IP reachability failures same as post roaming.

Add an experiment flag to control the behavior of handling other two
IP reachability failures(i.e. triggered from confirm or organic kernel
probe) the same as failure post roaming. Attempt to reduce the wifi
disconnection rate as much as possible caused by loss of reachability
to network neighbors.

Bug: 233684075
Test: atest com.android.server.wifi
Change-Id: Ic971f6f61c9085848c93408dc314a113387bb7ac
4 files changed