Revert "frameworks/base: IPV6 tethering support"

This reverts commit e21dcdbc042c0a069b20ff6e122a7b9e14ead57e.

Conflicts:
	services/java/com/android/server/connectivity/Tethering.java

Change-Id: I9eedfe5fe7a298f5cd87438306e34e8362680222
Other things about reboot

Change-Id: I6ecc365a2abc03ec4ac90e3c22e14eb754ab8660
Signed-off-by: Alberto97 <albertop2197@gmail.com>