sepolicy: make postinstall permissive

Change-Id: I005669b31598a8917a1e70dc3284bdb857763955
diff --git a/sepolicy/twrp.te b/sepolicy/twrp.te
index 2a5961f..5ed1e88 100755
--- a/sepolicy/twrp.te
+++ b/sepolicy/twrp.te
@@ -4,10 +4,10 @@
   permissive logd;
   permissive adbd;
   permissive fastbootd;
+  permissive postinstall;
   allow kernel unlabeled:file rw_file_perms;
   allow kernel tmpfs:file { read };
   allow kernel recovery:fd { use };
   allow unlabeled unlabeled:filesystem associate;
   allow vendor_init rootfs:dir read;
-  allow postinstall tmpfs:file { getattr read execute };
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