Omni: Update backuptools version

Change-Id: I94ea75203b35a68b4580310f510e20b70fc2b204
diff --git a/prebuilt/bin/backuptool.sh b/prebuilt/bin/backuptool.sh
index 17e1032..da0c95c 100755
--- a/prebuilt/bin/backuptool.sh
+++ b/prebuilt/bin/backuptool.sh
@@ -5,7 +5,7 @@
 
 export C=/tmp/backupdir
 export S=/system
-export V=4.3
+export V=4.4
 
 # Preserve /system/addon.d in /tmp/addon.d
 preserve_addon_d() {