Move 'privapp_whitelist_com.android.launcher3' to system_ext

As AOSP launcher is moved to system_ext, its permission files will follow the app location.

Test: m
Bug: 137908189
Change-Id: I5d11e3901633be82f375c56a5ef2c79b6e0b0922
diff --git a/data/etc/Android.bp b/data/etc/Android.bp
index ff521be..43f65e3 100644
--- a/data/etc/Android.bp
+++ b/data/etc/Android.bp
@@ -88,7 +88,7 @@
 
 prebuilt_etc {
     name: "privapp_whitelist_com.android.launcher3",
-    product_specific: true,
+    system_ext_specific: true,
     sub_dir: "permissions",
     src: "com.android.launcher3.xml",
     filename_from_src: true,