Revert "changed to custom keys"

This reverts commit 53c2836084de709b8cccf205127ea3b2719622b1.

Conflicts:
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_back.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_back_ime.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_back_land.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_home.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_home_land.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_recent.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_recent_land.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_back.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_back_ime.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_back_land.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_home.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_home_land.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_recent.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_recent_land.png