Revert "Build empty test apk until junit dependency issue is sorted out."

This reverts commit 4c82c33a64b9f6719a0a1457361362cf70e2c9ac.

Change-Id: I39c142e2b0e882245a6928264465578e4ddc12c9
diff --git a/tests/Android.mk b/tests/Android.mk
index 466146e..5103ced 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -17,9 +17,9 @@
 include $(CLEAR_VARS)
 
 LOCAL_MODULE_TAGS := tests
-#LOCAL_STATIC_JAVA_LIBRARIES := android-support-test ub-uiautomator mockito-target-minus-junit4
+LOCAL_STATIC_JAVA_LIBRARIES := android-support-test ub-uiautomator mockito-target-minus-junit4
 
-#LOCAL_SRC_FILES := $(call all-java-files-under, src)
+LOCAL_SRC_FILES := $(call all-java-files-under, src)
 
 LOCAL_SDK_VERSION := current
 LOCAL_MIN_SDK_VERSION := 21