fix WRITE_SETTINGS to be "dangerous"

(see http://www.fireeye.com/blog/technical/2014/04/occupy_your_icons_silently_on_android.html for an explanation why this is dangerous)

Change-Id: I8f938dc4f528aa2ccbca3d4cec235feb0299c0bd
Return: Custom Carrier Label [1/2]

PS 3 : Fix code style
PS 5 : Rebase
PS 6 : Fix derp

Change-Id: Ic865e3c5204ab05f1e9ab0e081a54b155b577086

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/policy/NetworkController.java