procrank: fix procrank when run from dumpstate

Commit a1913988 added a new
SELinux label to /system/xbin/procrank, which had the effect of
preventing dumpstate from executing procrank. Allow dumpstate
to execute procrank.

Bug: 18342188
Change-Id: If5b781db0d3af34912f3c803b7fa73d53120f3ba

procrank.te

@@ -5,9 +5,11 @@ userdebug_or_eng(`
   type procrank, domain, mlstrustedsubject;
 
   domain_auto_trans(shell, procrank_exec, procrank)
+  domain_auto_trans(dumpstate, procrank_exec, procrank)
   allow procrank self:capability sys_ptrace;
   allow procrank devpts:chr_file { read write getattr ioctl };
+  allow procrank dumpstate:unix_stream_socket { read write getattr };
   r_dir_file(procrank, domain)
-  allow procrank shell:fd use;
+  allow procrank { shell dumpstate }:fd use;
   allow procrank adbd:process sigchld;
 ')