Fixes ProGuard options.

1. Dedup LOCAL_JAVA_LIBRARIES.
2. Even no resource or asset for a package, we still need to set
package_expected_intermediates_COMMON, which is anyway used by ProGuard.

core/java.mk

@@ -28,6 +28,7 @@ else
     LOCAL_JAVA_LIBRARIES := core ext framework $(LOCAL_JAVA_LIBRARIES)
   endif
 endif
+LOCAL_JAVA_LIBRARIES := $(sort $(LOCAL_JAVA_LIBRARIES))
 
 LOCAL_BUILT_MODULE_STEM := $(strip $(LOCAL_BUILT_MODULE_STEM))
 ifeq ($(LOCAL_BUILT_MODULE_STEM),)