fix(deps): update kotlin monorepo to v2.1.20-beta1

example/android/app/build.gradle

@@ -112,5 +112,5 @@ flutter {
 }
 
 dependencies {
-    implementation platform("org.jetbrains.kotlin:kotlin-bom:2.1.0")
+    implementation platform("org.jetbrains.kotlin:kotlin-bom:2.1.20-Beta1")
 }

example/android/settings.gradle

@@ -41,7 +41,7 @@ pluginManagement {
 plugins {
     id "dev.flutter.flutter-plugin-loader" version "1.0.0"
     id "com.android.application" version "8.4.2" apply false
-    id "org.jetbrains.kotlin.android" version "2.1.0" apply false
+    id "org.jetbrains.kotlin.android" version "2.1.20-Beta1" apply false
 }
 
 include ":app"