[java][okhttp] Add CI tests for streaming (#10678)

* add ci tests for streaming

* use spaces instead of tabs

* update samples

samples/client/others/java/okhttp-gson-streaming/.openapi-generator/FILES

@@ -0,0 +1,36 @@
+.gitignore
+.travis.yml
+README.md
+api/openapi.yaml
+build.gradle
+build.sbt
+docs/PingApi.md
+docs/SomeObj.md
+git_push.sh
+gradle.properties
+gradle/wrapper/gradle-wrapper.jar
+gradle/wrapper/gradle-wrapper.properties
+gradlew
+gradlew.bat
+pom.xml
+settings.gradle
+src/main/AndroidManifest.xml
+src/main/java/org/openapitools/client/ApiCallback.java
+src/main/java/org/openapitools/client/ApiClient.java
+src/main/java/org/openapitools/client/ApiException.java
+src/main/java/org/openapitools/client/ApiResponse.java
+src/main/java/org/openapitools/client/Configuration.java
+src/main/java/org/openapitools/client/GzipRequestInterceptor.java
+src/main/java/org/openapitools/client/JSON.java
+src/main/java/org/openapitools/client/Pair.java
+src/main/java/org/openapitools/client/ProgressRequestBody.java
+src/main/java/org/openapitools/client/ProgressResponseBody.java
+src/main/java/org/openapitools/client/ServerConfiguration.java
+src/main/java/org/openapitools/client/ServerVariable.java
+src/main/java/org/openapitools/client/StringUtil.java
+src/main/java/org/openapitools/client/api/PingApi.java
+src/main/java/org/openapitools/client/auth/ApiKeyAuth.java
+src/main/java/org/openapitools/client/auth/Authentication.java
+src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+src/main/java/org/openapitools/client/model/SomeObj.java

samples/client/others/java/okhttp-gson-streaming/.openapi-generator/VERSION

@@ -0,0 +1 @@
+5.3.0-SNAPSHOT