Relabel drm related props from exported*_prop

To clean up bad context name exported[23]_default_prop

Bug: 155844385
Test: m selinux_policy
Change-Id: I9f9ddb0d44c4cea9bd1724df730bb7be9a6fb2d2
diff --git a/private/mediaserver.te b/private/mediaserver.te
index fa2fc08..7fb8029 100644
--- a/private/mediaserver.te
+++ b/private/mediaserver.te
@@ -13,4 +13,5 @@
 
 set_prop(mediaserver, audio_prop)
 
+get_prop(mediaserver, drm_service_config_prop)
 get_prop(mediaserver, media_config_prop)