update: add missing newline at end of OptimizelyDecisionsCallback.java

Author: FarhanAnjum-opti

core-api/src/main/java/com/optimizely/ab/optimizelydecision/OptimizelyDecisionsCallback.java

@@ -29,4 +29,4 @@ public interface OptimizelyDecisionsCallback {
      * @param decisions Map of flag keys to decision results
      */
     void onCompleted(@Nonnull Map<String, OptimizelyDecision> decisions);
-}
+}