Allow priv apps to use virtualizationservice

And allow VS and crosvm access to privapp_data_file, to the same
extent as app_data_file.

Update some comments, move a neverallow to the bottom of the file with
the others.

Bug: 255286871
Test: Install demo app to system/priv-app, see it work without explicit grant.
Change-Id: Ic763c3fbfdfe9b7a7ee6f1fe76d2a74281b69f4f
diff --git a/private/virtualizationservice.te b/private/virtualizationservice.te
index 6e6b459..3e057fe 100644
--- a/private/virtualizationservice.te
+++ b/private/virtualizationservice.te
@@ -44,6 +44,7 @@
 allow virtualizationservice {
   app_data_file
   apex_compos_data_file
+  privapp_data_file
 }:file { getattr read write };
 
 # shell_data_file is used for automated tests and manual debugging.