omni: Make A/B backuptool permissive

Change-Id: Ib1f52f40dab26ac4575e06bfd54b88809b00f8d3
diff --git a/sepolicy/private/backuptool.te b/sepolicy/private/backuptool.te
new file mode 100644
index 0000000..f5a9b2d
--- /dev/null
+++ b/sepolicy/private/backuptool.te
@@ -0,0 +1,5 @@
+type backuptool, domain, coredomain;
+
+permissive backuptool;
+
+neverallow { domain -update_engine } backuptool:process transition;