Use Android L navbar icons by default

Change-Id: I80425aec8db26e56954c0c081ee811eeff86e4fd

Conflicts:
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_back.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_back_ime.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_back_land.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_home.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_home_land.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_menu.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_menu_big.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_recent.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_recent_land.png
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_search.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_back.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_back_ime.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_back_land.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_home.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_home_land.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_menu.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_menu_big.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_recent.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_recent_land.png
	packages/SystemUI/res/drawable-mdpi/ic_sysbar_search.png
	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_menu.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_menu_big.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_recent.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_recent_land.png
	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_search.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_menu.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_menu_big.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_recent.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_recent_land.png
	packages/SystemUI/res/drawable-xxhdpi/ic_sysbar_search.png