Add missing selinux permissions for mediacodec

Bug: 27305063
Change-Id: Ie9ac3fb971dbb989d7b26421e076139d3f48a916
diff --git a/mediacodec.te b/mediacodec.te
index 9958f17..b3848ca 100644
--- a/mediacodec.te
+++ b/mediacodec.te
@@ -15,7 +15,7 @@
 allow mediacodec gpu_device:chr_file rw_file_perms;
 allow mediacodec video_device:chr_file rw_file_perms;
 allow mediacodec video_device:dir search;
-allow mediacodec ion_device:chr_file r_file_perms;
+allow mediacodec ion_device:chr_file rw_file_perms;
 
 ###
 ### neverallow rules