changed target version

examplemultipleports/build.gradle

@@ -1,19 +1,15 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 28
-
 
+    compileSdkVersion Integer.parseInt(project.ANDROID_BUILD_SDK_VERSION)
 
     defaultConfig {
         applicationId "com.felhr.examplemultipleports"
-        minSdkVersion 17
-        targetSdkVersion 28
-        versionCode 1
-        versionName "1.0"
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
+        minSdkVersion Integer.parseInt(project.ANDROID_BUILD_MIN_SDK_VERSION)
+        targetSdkVersion Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION)
+        versionName project.VERSION_NAME
+        versionCode Integer.parseInt(project.VERSION_CODE)
     }
 
     compileOptions {
@@ -32,13 +28,17 @@ android {
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'com.android.support:support-v4:23.1.1'
+    implementation 'com.android.support:appcompat-v7:23.1.1'
+    implementation 'com.android.support:design:23.1.1'
+
+    implementation 'com.android.support:support-annotations:28.0.0'
 
-    implementation 'com.android.support:appcompat-v7:28.0.0'
-    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
-    testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    androidTestImplementation 'junit:junit:4.12'
+
+    testImplementation 'junit:junit:4.12'
 
     implementation project(':usbserial')
     implementation 'com.annimon:stream:1.2.1'