selinux: Update policies for mediadrmserver

DRM 3rd party application with platform signature
requires the permission.

Bug: 30352348
Change-Id: Idd673506764ae435db1be8cc8c13658541ffa687
diff --git a/platform_app.te b/platform_app.te
index 0d3bdba..d4a27ad 100644
--- a/platform_app.te
+++ b/platform_app.te
@@ -45,6 +45,7 @@
 allow platform_app mediaserver_service:service_manager find;
 allow platform_app mediaextractor_service:service_manager find;
 allow platform_app mediacodec_service:service_manager find;
+allow platform_app mediadrmserver_service:service_manager find;
 allow platform_app persistent_data_block_service:service_manager find;
 allow platform_app radio_service:service_manager find;
 allow platform_app surfaceflinger_service:service_manager find;