add mediatranscoding to apex file context am: 9aed64920f

Original change: https://android-review.googlesource.com/c/platform/system/sepolicy/+/1522099

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibc15a90266d1f30174d6590a157571507e8ee31a
diff --git a/apex/com.android.media-file_contexts b/apex/com.android.media-file_contexts
index f6b21da..8822046 100644
--- a/apex/com.android.media-file_contexts
+++ b/apex/com.android.media-file_contexts
@@ -1,2 +1,3 @@
 (/.*)?                u:object_r:system_file:s0
 /lib(64)?(/.*)        u:object_r:system_lib_file:s0
+/bin/mediatranscoding     u:object_r:mediatranscoding_exec:s0