Add turn off action to WiFi Tether notification

Change-Id: I320405ed7e90e4c06ecdb127cd4c1cad6bedbcdd
Signed-off-by: Gergely Szell (sethyx) <szell@hu.ibm.com>

Conflicts:
	core/res/res/values/strings.xml
	core/res/res/values/symbols.xml