sepolicy: actually include mediaserver.te

Added in patch e9c2de0679f16a8ba7291aaf2cd4286bef8b2886 but not included

Change-Id: I2ae901a7c80fceb33dba2ed4122d2aa47bff5a51
diff --git a/sepolicy/sepolicy.mk b/sepolicy/sepolicy.mk
index f5395eb..6cd5064 100644
--- a/sepolicy/sepolicy.mk
+++ b/sepolicy/sepolicy.mk
@@ -21,6 +21,7 @@
     healthd.te \
     hostapd.te \
     installd.te \
+    mediaserver.te \
     netd.te \
     property.te \
     recovery.te \