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/public/hal_cas.te b/public/hal_cas.te
index 7de6a13..e699a6b 100644
--- a/public/hal_cas.te
+++ b/public/hal_cas.te
@@ -16,6 +16,10 @@
 allow hal_cas cgroup:dir { search write };
 allow hal_cas cgroup:file w_file_perms;
 
+r_dir_file(hal_cas, cgroup_v2)
+allow hal_cas cgroup_v2:dir { search write };
+allow hal_cas cgroup_v2:file w_file_perms;
+
 # Allow access to ion memory allocation device
 allow hal_cas ion_device:chr_file rw_file_perms;
 allow hal_cas hal_graphics_allocator:fd use;