Add CleanupPreviousUpdate in a few missing places

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

Change-Id: I99ac444eda38974838ff5867b9f86bea01d61500
diff --git a/update_manager/real_updater_provider.cc b/update_manager/real_updater_provider.cc
index 134db69..1f9af0d 100644
--- a/update_manager/real_updater_provider.cc
+++ b/update_manager/real_updater_provider.cc
@@ -169,6 +169,8 @@
      Stage::kReportingErrorEvent},
     {update_engine::kUpdateStatusAttemptingRollback,
      Stage::kAttemptingRollback},
+    {update_engine::kUpdateStatusCleanupPreviousUpdate,
+     Stage::kCleanupPreviousUpdate},
 };
 
 const Stage* StageVariable::GetValue(TimeDelta /* timeout */, string* errmsg) {