Allow mediacodec access to sync fences.

Test: WIP
Change-Id: I678b0d0e9750b25628b86060574fd516d3749cdf

public/mediacodec.te

@@ -20,6 +20,9 @@ binder_call(mediacodec, binderservicedomain)
 binder_call(mediacodec, appdomain)
 binder_service(mediacodec)
 
+# Allow mediacodec access to composer sync fences
+allow mediacodec hal_graphics_composer:fd use;
+
 # TODO(b/36604251): Remove this once OMX HAL stops using Binder
 typeattribute mediacodec binder_in_vendor_violators;
 add_service(mediacodec, mediacodec_service)