Vendors may choose dm-default-key options format

Bug: 150761030
Test: setting to 1 in device/google/cuttlefish/shared/device.mk
    causes "default-key: Not enough arguments" as expected.
Change-Id: I73262efff0be15f0295d23168049ed9e3721a7f7
diff --git a/private/property_contexts b/private/property_contexts
index 5baaf9d..6c4f43b 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -394,6 +394,7 @@
 ro.crypto.allow_encrypt_override     u:object_r:exported2_vold_prop:s0 exact bool
 ro.crypto.fde_algorithm              u:object_r:exported2_vold_prop:s0 exact string
 ro.crypto.fde_sector_size            u:object_r:exported2_vold_prop:s0 exact int
+ro.crypto.dm_default_key.options_format.version u:object_r:exported2_vold_prop:s0 exact int
 ro.crypto.scrypt_params              u:object_r:exported2_vold_prop:s0 exact string
 ro.crypto.set_dun                    u:object_r:exported2_vold_prop:s0 exact bool
 ro.crypto.volume.contents_mode       u:object_r:exported2_vold_prop:s0 exact string