Fix the refCnt exception (#1362)

Fix the concurrency issue that causes release to be called for the object twice.

Author: justinlin-linkedin

ambry-router/src/main/java/com.github.ambry.router/GetBlobOperation.java

@@ -433,8 +433,6 @@ private void maybeWriteToChannel() {
      */
     void completeRead() {
       if (readIntoCallbackCalled.compareAndSet(false, true)) {
-        chunkIndexToResponseInfo.values().forEach(ResponseInfo::release);
-        chunkIndexToResponseInfo.clear();
         Exception e = operationException.get();
         readIntoFuture.done(bytesWritten.get(), e);
         if (readIntoCallback != null) {
@@ -451,6 +449,12 @@ void completeRead() {
         } else {
           routerMetrics.getBlobOperationTotalTimeMs.update(totalTime);
         }
+        for (Integer key : chunkIndexToResponseInfo.keySet()) {
+          ResponseInfo response = chunkIndexToResponseInfo.remove(key);
+          if (response != null) {
+            response.release();
+          }
+        }
       }
       operationCompleted = true;
     }