plugin: 'kotlin-android-extensions' deprecrated

use viewbinding
see: https://developer.android.com/topic/libraries/view-binding/migration

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

build.gradle

@@ -31,7 +31,6 @@ buildscript {
 apply plugin: 'com.android.application'
 
 apply plugin: 'kotlin-android'
-apply plugin: 'kotlin-android-extensions'
 apply plugin: 'kotlin-kapt'
 apply plugin: 'checkstyle'
 apply plugin: 'pmd'