fix missing jackson-databind-nullable in okhttp java client (#10078)

samples/client/petstore/java/okhttp-gson-dynamicOperations/build.gradle

@@ -104,6 +104,7 @@ dependencies {
     implementation 'com.squareup.okhttp3:logging-interceptor:4.9.1'
     implementation 'com.google.code.gson:gson:2.8.6'
     implementation 'io.gsonfire:gson-fire:1.8.4'
+    implementation 'org.openapitools:jackson-databind-nullable:0.2.1'
     implementation group: 'org.apache.oltu.oauth2', name: 'org.apache.oltu.oauth2.client', version: '1.0.1'
     implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.10'
     implementation 'org.threeten:threetenbp:1.4.3'

samples/client/petstore/java/okhttp-gson-dynamicOperations/build.sbt

@@ -14,6 +14,7 @@ lazy val root = (project in file(".")).
       "com.squareup.okhttp3" % "logging-interceptor" % "4.9.1",
       "com.google.code.gson" % "gson" % "2.8.6",
       "org.apache.commons" % "commons-lang3" % "3.10",
+      "org.openapitools" % "jackson-databind-nullable" % "0.2.1",
       "org.apache.oltu.oauth2" % "org.apache.oltu.oauth2.client" % "1.0.1",
       "org.threeten" % "threetenbp" % "1.4.3" % "compile",
       "io.swagger.parser.v3" % "swagger-parser-v3" "2.0.23" % "compile"

samples/client/petstore/java/okhttp-gson-dynamicOperations/pom.xml

@@ -267,6 +267,11 @@
             <version>${javax-annotation-version}</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
         <!-- test dependencies -->
         <dependency>
             <groupId>junit</groupId>
@@ -284,6 +289,7 @@
         <okhttp-version>4.9.1</okhttp-version>
         <gson-version>2.8.6</gson-version>
         <commons-lang3-version>3.11</commons-lang3-version>
+        <jackson-databind-nullable-version>0.2.1</jackson-databind-nullable-version>
         <threetenbp-version>1.5.0</threetenbp-version>
         <javax-annotation-version>1.3.2</javax-annotation-version>
         <junit-version>4.13.1</junit-version>