Add update_engine_host_unittests

Some of update_engine's codebase (payload generator stuff) run on host.
So it make sense to test them on the host. Adding a new unittest target
update_engine_host_unittests, which includes a subset of unittest. After
this CL, the old update_engine_unittests target remains unchanged, it
still contains all 600 unittests. The new host target will contain a
subset of these.

Test: th
Change-Id: I49c8310cee9a2b2ea197b8ab60ea3b00bf5680cf
diff --git a/update_status_utils.cc b/update_status_utils.cc
index a702c61..6b96dda 100644
--- a/update_status_utils.cc
+++ b/update_status_utils.cc
@@ -18,7 +18,6 @@
 #include <base/logging.h>
 #include <base/strings/string_number_conversions.h>
 #include <brillo/key_value_store.h>
-#include <update_engine/dbus-constants.h>
 
 using brillo::KeyValueStore;
 using std::string;
@@ -40,6 +39,27 @@
 const char kProgress[] = "PROGRESS";
 const char kWillPowerwashAfterReboot[] = "WILL_POWERWASH_AFTER_REBOOT";
 
+namespace update_engine {
+const char kUpdateStatusIdle[] = "UPDATE_STATUS_IDLE";
+const char kUpdateStatusCheckingForUpdate[] =
+    "UPDATE_STATUS_CHECKING_FOR_UPDATE";
+const char kUpdateStatusUpdateAvailable[] = "UPDATE_STATUS_UPDATE_AVAILABLE";
+const char kUpdateStatusDownloading[] = "UPDATE_STATUS_DOWNLOADING";
+const char kUpdateStatusVerifying[] = "UPDATE_STATUS_VERIFYING";
+const char kUpdateStatusFinalizing[] = "UPDATE_STATUS_FINALIZING";
+const char kUpdateStatusUpdatedNeedReboot[] =
+    "UPDATE_STATUS_UPDATED_NEED_REBOOT";
+const char kUpdateStatusReportingErrorEvent[] =
+    "UPDATE_STATUS_REPORTING_ERROR_EVENT";
+const char kUpdateStatusAttemptingRollback[] =
+    "UPDATE_STATUS_ATTEMPTING_ROLLBACK";
+const char kUpdateStatusDisabled[] = "UPDATE_STATUS_DISABLED";
+const char kUpdateStatusNeedPermissionToUpdate[] =
+    "UPDATE_STATUS_NEED_PERMISSION_TO_UPDATE";
+const char kUpdateStatusCleanupPreviousUpdate[] =
+    "UPDATE_STATUS_CLEANUP_PREVIOUS_UPDATE";
+}  // namespace update_engine
+
 }  // namespace
 
 const char* UpdateStatusToString(const UpdateStatus& status) {