Moving junit out of core.jar and into core-junit.jar

This commit was submitted too early:
   https://android-git.corp.google.com/g/50610
...and then rolled back:
   https://android-git.corp.google.com/g/50622

Change-Id: I5f4e53bd0c892ab64711b99b2e95d2f101626dbc
diff --git a/core/java.mk b/core/java.mk
index 137a730..e7a1a51 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -29,7 +29,7 @@
   endif
 else
   ifneq ($(LOCAL_NO_STANDARD_LIBRARIES),true)
-    LOCAL_JAVA_LIBRARIES := core ext framework $(LOCAL_JAVA_LIBRARIES)
+    LOCAL_JAVA_LIBRARIES := core core-junit ext framework $(LOCAL_JAVA_LIBRARIES)
   endif
 endif
 LOCAL_JAVA_LIBRARIES := $(sort $(LOCAL_JAVA_LIBRARIES))