Support ignoring validation failures after roam.

In some scenarios, Wi-Fi connectivity is disrupted after roam. If an application reacts to network errors by calling reportNetworkConnectivity(false), validation will immediately fail and the device will switch to cell data.

Add a way to ignore these validation failures for up to 10 seconds after Wi-Fi roams.

Bug: 216567577
Test: new unit tests

Change-Id: I58de486533bcc7c6e32b23536ae15bccb779e394
5 files changed