Union sepolicy within TWRP to make SELinux permissive

This patch set should make it easier to build TWRP in non-Omni
trees as it allows TWRP to modify the sepolicy instead of having
to merge a patch in external/sepolicy to meet TWRP's needs.

Change-Id: I73205343556abb0852ff4c5f8cbf293d840b95d9
diff --git a/sepolicy/twrp.te b/sepolicy/twrp.te
new file mode 100644
index 0000000..3ebdc4b
--- /dev/null
+++ b/sepolicy/twrp.te
@@ -0,0 +1 @@
+permissive recovery;