Add CleanupPreviousUpdate in a few missing places

Bug: 163153182
Test: FEATURES=test emerge-reef update_engine

Change-Id: I99ac444eda38974838ff5867b9f86bea01d61500
diff --git a/update_manager/updater_provider.h b/update_manager/updater_provider.h
index cb62623..81ffb41 100644
--- a/update_manager/updater_provider.h
+++ b/update_manager/updater_provider.h
@@ -36,6 +36,7 @@
   kUpdatedNeedReboot,
   kReportingErrorEvent,
   kAttemptingRollback,
+  kCleanupPreviousUpdate,
 };
 
 enum class UpdateRequestStatus {