system_server: allow appending to `debuggerd -j` pipe.

am: 5ca755e0

Change-Id: I92b326f5f1c9f1db083c329ecc8eca952039dc06

private/system_server.te

@@ -379,6 +379,10 @@ unix_socket_connect(system_server, tombstoned_java_trace, tombstoned)
 allow system_server tombstoned:fd use;
 allow system_server dumpstate:fifo_file append;
 allow system_server incidentd:fifo_file append;
+# Write to a pipe created from `adb shell` (for debuggerd -j `pidof system_server`)
+userdebug_or_eng(`
+  allow system_server su:fifo_file append;
+')
 
 # Read /data/misc/incidents - only read. The fd will be sent over binder,
 # with no DAC access to it, for dropbox to read.