snapshotctl: talk to bootcontrol HAL

Test: OTA then merge
Change-Id: Ifdb23070de4e7d8ae4a7ef7d5a6435f101c8b410
diff --git a/private/snapshotctl.te b/private/snapshotctl.te
index d07af3b..0f0313c 100644
--- a/private/snapshotctl.te
+++ b/private/snapshotctl.te
@@ -30,3 +30,7 @@
 
 # Needed to mutate device-mapper nodes.
 allow snapshotctl self:global_capability_class_set sys_admin;
+
+# Snapshotctl talk to boot control HAL to set merge status.
+hwbinder_use(snapshotctl)
+hal_client_domain(snapshotctl, hal_bootctl)