fix(Speech to Text): Fix method for sending new corpus file

Author: lpatino10

speech-to-text/src/main/java/com/ibm/watson/developer_cloud/speech_to_text/v1/SpeechToText.java

@@ -79,10 +79,8 @@
 import com.ibm.watson.developer_cloud.util.Validator;
 import okhttp3.HttpUrl;
 import okhttp3.MediaType;
-import okhttp3.MultipartBody;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
-import okhttp3.RequestBody;
 import okhttp3.WebSocket;
 
 /**
@@ -889,11 +887,7 @@ public ServiceCall<Void> addCorpus(AddCorpusOptions addCorpusOptions) {
     if (addCorpusOptions.allowOverwrite() != null) {
       builder.query("allow_overwrite", String.valueOf(addCorpusOptions.allowOverwrite()));
     }
-    MultipartBody.Builder multipartBuilder = new MultipartBody.Builder();
-    multipartBuilder.setType(MultipartBody.FORM);
-    RequestBody corpusFileBody = RequestUtils.inputStreamBody(addCorpusOptions.corpusFile(), "text/plain");
-    multipartBuilder.addFormDataPart("corpus_file", addCorpusOptions.corpusFilename(), corpusFileBody);
-    builder.body(multipartBuilder.build());
+    builder.body(RequestUtils.inputStreamBody(addCorpusOptions.corpusFile(), "text/plain"));
     return createServiceCall(builder.build(), ResponseConverterUtils.getVoid());
   }