I\'m setting up some tests and it will require a decent number of phones to be usb tethered and configured. I\'ve been successful in configuring them the way I want to once
For Android 5.0+ (Lollipop, Marshmallow) use:
adb shell su -c service call connectivity 30 i32 1 to turn USB Tethering ON
adb shell su -c service call connectivity 30 i32 1
adb shell su -c service call connectivity 30 i32 0 to turn USB Tethering OFF
adb shell su -c service call connectivity 30 i32 0
Keep in mind that this requires root.