[1/2] frameworks: bring back the status bar activity indicators for mobile data and wifi

Google were nice enough to create xxhdpi drawables for us before removing them.

Reverts "Remove signal/wifi activity indicator icon overlays."

This reverts commit fcc901c10bffdfb9c6b31e676dec36b47d949979.

Included NetworkController.java modification from Iaaa556ffab3ed4be1da8016ed40d0a9c2efcde01

Adding preference for arrows

PS14: Fixing errors

PS15: Turning arrows off done via actual removing drawables work, so when arrows are turned off,
they do not redraw statusbar anymore :-[

PS16: Commit Iaaa556ffab3ed4be1da8016ed40d0a9c2efcde01 merged to this one

PS17: Rebase to allow merge with latest source

Change-Id: I7aa85f7c8442c45d17e42cac7823dfe93e3f24c1
[1/2] SystemUI: Network speed indicator

Omni change id: I88e7cdfe20342c695a33383db36bf80bb4ffe009

Appeared after
http://forum.xda-developers.com/showpost.php?p=50643911&postcount=3361

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/res/values/colors.xml

PS3: Rebase

Change-Id: I2cc12bd888d592ea9c3a401b859b63a254614a18