Allow fallback crash dumping for seccomped processes.

Let mediacodec and mediaextractor talk directly to tombstoned to
generate tombstones/ANR traces.

Bug: http://b/35858739
Test: debuggerd -b `pidof media.codec`
Change-Id: I091be946d58907c5aa7a2fe23995597638adc896
diff --git a/public/mediacodec.te b/public/mediacodec.te
index a7d7807..99ebdb1 100644
--- a/public/mediacodec.te
+++ b/public/mediacodec.te
@@ -19,6 +19,7 @@
 allow mediacodec hal_graphics_allocator:fd use;
 allow mediacodec hal_camera:fd use;
 
+crash_dump_fallback(mediacodec)
 
 # hidl access
 hwbinder_use(mediacodec)