build error fix (#480)

android/build.gradle

@@ -40,10 +40,11 @@ android {
         main.java.srcDirs += 'src/main/kotlin'
     }
     defaultConfig {
-        minSdkVersion 21
-         if (project.android.hasProperty('namespace')) {
-        namespace 'io.github.ponnamkarthik.toast.fluttertoast'
-    }
+        // from flutter sdk 3.2 minSdkVersion
+        minSdkVersion 19
+        if (project.android.hasProperty('namespace')) {
+            namespace 'io.github.ponnamkarthik.toast.fluttertoast'
+        }
     }
     lintOptions {
         disable 'InvalidPackage'

example/android/app/build.gradle

@@ -47,7 +47,7 @@ android {
         applicationId "com.example.example"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-build-configuration.
-        minSdkVersion 21
+        minSdkVersion flutter.minSdkVersion
         targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName