SEPolicy: Changes for new stack dumping scheme.

Applications connect to tombstoned via a unix domain socket and request
an open FD to which they can write their traces. This socket has a new
label (tombstoned_java_trace_socket) and appdomain and system_server are
given permissions to connect and write to it.

Apps no longer need permissions to open files under /data/anr/ and
these permissions will be withdrawn in a future change.

Bug: 32064548
Test: Manual

(cherry picked from commit a8832dabc7f3b7b2381760d2b95f81abf78db709)

Change-Id: I70a3e6e230268d12b454e849fa88418082269c4f
diff --git a/private/file_contexts b/private/file_contexts
index 73f4a7f..691605a 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -146,6 +146,7 @@
 /dev/socket/rild	u:object_r:rild_socket:s0
 /dev/socket/rild-debug	u:object_r:rild_debug_socket:s0
 /dev/socket/tombstoned_crash u:object_r:tombstoned_crash_socket:s0
+/dev/socket/tombstoned_java_trace u:object_r:tombstoned_java_trace_socket:s0
 /dev/socket/tombstoned_intercept u:object_r:tombstoned_intercept_socket:s0
 /dev/socket/uncrypt	u:object_r:uncrypt_socket:s0
 /dev/socket/vold	u:object_r:vold_socket:s0