fix broken user build: do not throw an error when in user flavor.

Change-Id: I43d210f1b342707acbdb79f9ef6c924b43684dd3

Author: Tsu Chiang Chuang

core/tests/hosttests/test-apps/DownloadManagerTestApp/Android.mk

@@ -26,10 +26,8 @@ LOCAL_SDK_VERSION := current
 LOCAL_PACKAGE_NAME := DownloadManagerTestApp
 
 ifneq ($(TARGET_BUILD_VARIANT),user)
-# Need to run as system app to get access to Settings.
+# Need to run as system app to get access to Settings. This test won't work for user builds.
 LOCAL_CERTIFICATE := platform
-else
-$(error "This test app will fail to run unless it is built in non-user mode.")
 endif
 
 include $(BUILD_PACKAGE)