Make system use patchoat to relocate during runtime.

Add patchoat selinux rules.

Bug: 15358152

Change-Id: Ibe92d8b55a24bbf718b0416a21b76e5df7a2de26

file_contexts

@@ -161,6 +161,8 @@
 /system/bin/vdc         u:object_r:vdc_exec:s0
 /system/bin/install-recovery.sh u:object_r:install_recovery_exec:s0
 /system/bin/dex2oat     u:object_r:dex2oat_exec:s0
+# patchoat executable has (essentially) the same requirements as dex2oat.
+/system/bin/patchoat    u:object_r:dex2oat_exec:s0
 
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 # Vendor files