sepolicy: rules for uid/pid cgroups v2 hierarchy

Bug: 168907513
Test: verified the correct working of the v2 uid/pid hierarchy in normal
and recovery modes

This reverts commit aa8bb3a29b92a342c42c802edac269da5984d1df.

Change-Id: Ib344d500ea49b86e862e223ab58a16601eebef47
diff --git a/private/priv_app.te b/private/priv_app.te
index 6e85b42..e5889d1 100644
--- a/private/priv_app.te
+++ b/private/priv_app.te
@@ -240,6 +240,7 @@
 
 # Do not allow priv_app access to cgroups.
 neverallow priv_app cgroup:file *;
+neverallow priv_app cgroup_v2:file *;
 
 # Do not allow loading executable code from non-privileged
 # application home directories. Code loading across a security boundary