crash_dump: suppress devpts denials

The following denial caused a presubmit failure:
06-15 15:16:24.176   956   956 I auditd  : type=1400 audit(0.0:4): avc:
denied { read write } for comm="crash_dump64" path="/dev/pts/3"
dev="devpts" ino=6 scontext=u:r:crash_dump:s0
tcontext=u:object_r:devpts:s0 tclass=chr_file permissive=0

Suppress these denials. They are not needed by crash_dump and are only
caused by the default behavior of sharing FDs across exec.

Test: build
Change-Id: I183f7a54e6b807fdf46b04d67dd4b819d4f0e507
diff --git a/private/crash_dump.te b/private/crash_dump.te
index adc46a1..f130327 100644
--- a/private/crash_dump.te
+++ b/private/crash_dump.te
@@ -1,7 +1,7 @@
 typeattribute crash_dump coredomain;
 
 # Crash dump does not need to access devices passed across exec().
-dontaudit crash_dump dev_type:chr_file { read write };
+dontaudit crash_dump { devpts dev_type }:chr_file { read write };
 
 allow crash_dump {
   domain