Update gradle plugin version and other properties

This was basically done by creating a new flutter project and comparing the
different generated files

android/app/build.gradle

@@ -44,12 +44,12 @@ if (localMapsPropertiesFile.exists()) {
     project.logger.info('Load maps properties from environment')
     try {
         wgerProperties['WGER_API_KEY'] = System.getenv('WGER_API_KEY')
-    } catch(NullPointerException e) {
+    } catch (NullPointerException e) {
         project.logger.warn('Failed to load WGER_API_KEY from environment.', e)
     }
 }
 def wgerApiKey = wgerProperties.getProperty('WGER_API_KEY')
-if(wgerApiKey == null){
+if (wgerApiKey == null) {
     wgerApiKey = ""
     project.logger.error('Wger Api Key not configured. Set it in `/fastlane/metadata/android/envfiles/wger.properties` or in the environment variable `WGER_API_KEY`')
 }
@@ -58,6 +58,15 @@ android {
     compileSdkVersion 33
     ndkVersion "25.1.8937393"
 
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
+
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }