Merge pull request #98 from Kaishley/patch-2

[Android] Removed duplicate code in RNFetchBlobBody.java

src/android/src/main/java/com/RNFetchBlob/RNFetchBlobBody.java

         return mime;
     }
     
-    @Override
-    public long contentLength() {
-        return contentLength;
-    }
-    
     @Override
     public void writeTo(BufferedSink sink) {
         try {