Allow drm hals to access allocator hal

Bug: 150468341
Test: atest VtsHalDrmV1_3TargetTest
Change-Id: Iea8934567cda343dedf17f75cb0807a68742764d
diff --git a/public/hal_drm.te b/public/hal_drm.te
index d86edaf..5987491 100644
--- a/public/hal_drm.te
+++ b/public/hal_drm.te
@@ -24,6 +24,9 @@
 allow hal_drm ion_device:chr_file rw_file_perms;
 allow hal_drm hal_graphics_allocator:fd use;
 
+# Allow access to hidl_memory allocation service
+allow hal_drm hal_allocator_server:fd use;
+
 # Allow access to fds allocated by mediaserver
 allow hal_drm mediaserver:fd use;