created two build api levels

Author: Your Name

android/app/build.gradle

@@ -37,16 +37,25 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "org.fossasia.badgemagic"
-        // You can update the following values to match your application needs.
-        // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
-        minSdkVersion 21
-        targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
     }
 
+    flavorDimensions "api"
+    productFlavors {
+        preApi30 {
+            dimension "api"
+            minSdkVersion 21
+            targetSdkVersion 29
+        }
+        postApi30 {
+            dimension "api"
+            minSdkVersion 30
+            targetSdkVersion 34
+        }
+    }
+
     signingConfigs {
         if (GITHUB_BUILD) {
             release {