Add SELinux policy changes for rkpd

This is a part of changes to bring up Remote Key Provisioning Daemon
module. See packages/modules/RemoteKeyProvisioning for more info.

Change-Id: Iae4e98176491637acb03e2e09b9d8dbc269be616
Test: atest rkpd_client_test
diff --git a/apex/Android.bp b/apex/Android.bp
index 8c9db86..994bfd2 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -272,3 +272,10 @@
     "com.android.healthconnect-file_contexts",
   ],
 }
+
+filegroup {
+  name: "com.android.rkpd-file_contexts",
+  srcs: [
+    "com.android.rkpd-file_contexts",
+  ],
+}