Block call on wifi connect back to google on your Android device
Block call on wifi connect means captive portals wont redirect to login anymore
To do that,
Follow the next steps
Connect your device to your PC and use adb:
settings put global captive_portal_detection_enabled 0
There is also a way to change the url it calls:
settings put global captive_portal_server localhost
but disabling probably the easiest.
Here you have a command to test the results.
settings get global captive_portal_detection_enabled
You can give those commands in a terminal app in android (you probably need root parmissions).