fix(gradle): Use newer version var

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

Author: AndyScherzinger

app/build.gradle

@@ -11,7 +11,7 @@ apply plugin: 'com.android.application'
 apply plugin: 'org.jetbrains.kotlin.android'
 
 android {
-    compileSdk 35
+    compileSdkVersion 35
     namespace = 'it.niedermann.owncloud.notes'
 
     defaultConfig {