Transcoding: Allow media transcoding to log metrics to statsd

Bug: 179274112
Test: Used statsd_testdrive to verify that metrics reach statsd
Change-Id: Ia63b522f7898e86dffe629bd41d76934c95b8aee
diff --git a/private/mediatranscoding.te b/private/mediatranscoding.te
index 5f4a943..372bde6 100644
--- a/private/mediatranscoding.te
+++ b/private/mediatranscoding.te
@@ -36,6 +36,9 @@
 allow mediatranscoding app_data_file:file { getattr read write };
 allow mediatranscoding shell_data_file:file { getattr read write };
 
+# allow mediatranscoding service write permission to statsd socket
+unix_socket_send(mediatranscoding, statsdw, statsd)
+
 # mediatranscoding should never execute any executable without a
 # domain transition
 neverallow mediatranscoding { file_type fs_type }:file execute_no_trans;