Set up sepolicy for mediaserver64

Add mediaserver(32|64) for supporting 64-bit only devices. The patch is
for setting up the sepolicy for mediaserver(32|64).

Bug: 236664614
Test: make gsi_arm64-user; Check the sepolicy
Change-Id: I61c69588b84305b9863a72b5a466d4185f7f1958
diff --git a/private/file_contexts b/private/file_contexts
index 09b53b5..de2c898 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -268,6 +268,8 @@
 /system/bin/audioserver	u:object_r:audioserver_exec:s0
 /system/bin/mediadrmserver	u:object_r:mediadrmserver_exec:s0
 /system/bin/mediaserver	u:object_r:mediaserver_exec:s0
+/system/bin/mediaserver32	u:object_r:mediaserver_exec:s0
+/system/bin/mediaserver64	u:object_r:mediaserver_exec:s0
 /system/bin/mediametrics	u:object_r:mediametrics_exec:s0
 /system/bin/cameraserver	u:object_r:cameraserver_exec:s0
 /system/bin/mediaextractor	u:object_r:mediaextractor_exec:s0