Add sepolicy for ro.virtual_ab.merge_delay_seconds

Bug: 311515963
Test: set ro.virtual_ab.merge_delay_seconds by PRODUCT_PROPERTY_OVERRIDES in mk files and run OTA
Change-Id: Ia9bac57879670e0dbd858705bffbb8dea7d58fba
diff --git a/private/property_contexts b/private/property_contexts
index 56ccb40..c8ced6d 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -338,6 +338,10 @@
 ro.virtual_ab.io_uring.enabled u:object_r:virtual_ab_prop:s0 exact bool
 ro.virtual_ab.compression.threads u:object_r:virtual_ab_prop:s0 exact bool
 ro.virtual_ab.batch_writes u:object_r:virtual_ab_prop:s0 exact bool
+# OEMs can set this prop at build time to configure how many seconds to delay
+# merge after installing a Virtual AB OTA. The default behavior is to start
+# merge immediately.
+ro.virtual_ab.merge_delay_seconds u:object_r:virtual_ab_prop:s0 exact int
 snapuserd.ready         u:object_r:snapuserd_prop:s0 exact bool
 snapuserd.proxy_ready   u:object_r:snapuserd_prop:s0 exact bool
 snapuserd.test.dm.snapshots u:object_r:snapuserd_prop:s0 exact bool