profcollectd: allow to call callbacks registered by system_server.

Bug: 213519191
Test: On oriole, profcollectd can call callbacks registered by
Test: ProfcollectForwardingService in system_server.
Change-Id: I8531a6e57e5e5c12033d5e8c7651ccff9a1d976a
diff --git a/private/profcollectd.te b/private/profcollectd.te
index efde321..f73990e 100644
--- a/private/profcollectd.te
+++ b/private/profcollectd.te
@@ -48,6 +48,8 @@
 
   # Allow profcollectd to publish a binder service and make binder calls.
   binder_use(profcollectd)
+  # Allow profcollectd to call callbacks registered by system_server when ETM is ready.
+  binder_call(profcollectd, system_server)
   add_service(profcollectd, profcollectd_service)
 
   # Allow to temporarily lift the kptr_restrict setting and get kernel start address