Add memory leak detection to audioserver

Bug: 28049120
Change-Id: Id288092402f36daafc3347db9b62d341a1de2eb3

audioserver.te

@@ -15,11 +15,14 @@ r_dir_file(audioserver, proc)
 allow audioserver ion_device:chr_file r_file_perms;
 allow audioserver system_file:dir r_dir_perms;
 
-# used for TEE sink - pcm capture for debug.
 userdebug_or_eng(`
+  # used for TEE sink - pcm capture for debug.
   allow audioserver media_data_file:dir create_dir_perms;
   allow audioserver audioserver_data_file:dir create_dir_perms;
   allow audioserver audioserver_data_file:file create_file_perms;
+
+  # ptrace to processes in the same domain for memory leak detection
+  allow audioserver self:process ptrace;
 ')
 
 allow audioserver audio_device:dir r_dir_perms;