Adding a new Edit Mode LauncherState

	- Edit Mode doesn't close after dragging / dropping an app
	- Edit Mode can be entered through options popup menu, Spring Loaded still entered by dragging items
	- Adds new onLeavingState call to launcher states to cleanup changes

Bug: 279590398
Flag: MULTI_SELECT_EDIT_MODE
Test: manually tested the new state with flag on/off

Change-Id: If4550037f9659dcb8cd8b1943388d1ec5d55fa29