Allow DISABLE_ALL_APPS to be set using a system property.

 - Moving the property to LauncherAppState
 - The property is only read on dogfood builds.

The property can be set using setprop or /data/local.prop

Change-Id: I14c7354efb12edb93f97e81687a6f920cc634e9a
diff --git a/src/com/android/launcher3/LauncherProvider.java b/src/com/android/launcher3/LauncherProvider.java
index 28efd01..1fb58cc 100644
--- a/src/com/android/launcher3/LauncherProvider.java
+++ b/src/com/android/launcher3/LauncherProvider.java
@@ -288,7 +288,7 @@
     }
 
     private static int getDefaultWorkspaceResourceId() {
-        if (AppsCustomizePagedView.DISABLE_ALL_APPS) {
+        if (LauncherAppState.isDisableAllApps()) {
             return R.xml.default_workspace_no_all_apps;
         } else {
             return R.xml.default_workspace;