update java petstore samples

samples/client/petstore/java/feign/build.gradle

@@ -9,8 +9,8 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.5.+'
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.3'
+        classpath 'com.android.tools.build:gradle:2.3.+'
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
     }
 }
 
@@ -23,19 +23,19 @@ if(hasProperty('target') && target == 'android') {
 
     apply plugin: 'com.android.library'
     apply plugin: 'com.github.dcendents.android-maven'
-    
+
     android {
-        compileSdkVersion 23
-        buildToolsVersion '23.0.2'
+        compileSdkVersion 25
+        buildToolsVersion '25.0.2'
         defaultConfig {
             minSdkVersion 14
-            targetSdkVersion 23
+            targetSdkVersion 25
         }
         compileOptions {
             sourceCompatibility JavaVersion.VERSION_1_7
             targetCompatibility JavaVersion.VERSION_1_7
         }
-    
+
         // Rename the aar correctly
         libraryVariants.all { variant ->
             variant.outputs.each { output ->
@@ -51,7 +51,7 @@ if(hasProperty('target') && target == 'android') {
             provided 'javax.annotation:jsr250-api:1.0'
         }
     }
-    
+
     afterEvaluate {
         android.libraryVariants.all { variant ->
             def task = project.tasks.create "jar${variant.name.capitalize()}", Jar
@@ -63,12 +63,12 @@ if(hasProperty('target') && target == 'android') {
             artifacts.add('archives', task);
         }
     }
-    
+
     task sourcesJar(type: Jar) {
         from android.sourceSets.main.java.srcDirs
         classifier = 'sources'
     }
-    
+
     artifacts {
         archives sourcesJar
     }
@@ -77,16 +77,16 @@ if(hasProperty('target') && target == 'android') {
 
     apply plugin: 'java'
     apply plugin: 'maven'
-    
+
     sourceCompatibility = JavaVersion.VERSION_1_7
     targetCompatibility = JavaVersion.VERSION_1_7
-    
+
     install {
         repositories.mavenInstaller {
             pom.artifactId = 'swagger-petstore-feign'
         }
     }
-    
+
     task execute(type:JavaExec) {
        main = System.getProperty('mainClass')
        classpath = sourceSets.main.runtimeClasspath