Add odsign status properties.

These properties are used to communicate odsign status, and allow init
to evict keys and start zygote at the correct moments in time.

Bug: 165630556
Test: no denials from init/odsign
Change-Id: I813e5c1c93d6f00a251a9cce02d0b74e5372c1ce
diff --git a/private/property.te b/private/property.te
index e435628..8ab02f0 100644
--- a/private/property.te
+++ b/private/property.te
@@ -22,6 +22,7 @@
 system_internal_prop(net_464xlat_fromvendor_prop)
 system_internal_prop(net_connectivity_prop)
 system_internal_prop(netd_stable_secret_prop)
+system_internal_prop(odsign_prop)
 system_internal_prop(pm_prop)
 system_internal_prop(rollback_test_prop)
 system_internal_prop(setupwizard_prop)