Rename property for default MTE mode.

This was requested in aosp/1959650.

Change-Id: I96f8771a39606b0934e4455991a6a34aea40235b
diff --git a/private/property_contexts b/private/property_contexts
index 05e5179..7106a51 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -707,7 +707,7 @@
 
 # shell-only props for ARM memory tagging (MTE).
 arm64.memtag. u:object_r:arm64_memtag_prop:s0 prefix string
-persist.arm64.memtag.mode u:object_r:arm64_memtag_prop:s0 exact string
+persist.arm64.memtag.default u:object_r:arm64_memtag_prop:s0 exact string
 
 net.redirect_socket_calls.hooked u:object_r:socket_hook_prop:s0 exact bool