fix(android): skip explicit Kotlin plugin when AGP provides built-in Kotlin

packages/analytics-react-native/android/build.gradle

@@ -13,7 +13,27 @@ if (findProject(':app') != null) {
 }
 
 apply plugin: "com.android.library"
-apply plugin: "kotlin-android"
+// Android Gradle Plugin 9 ships built-in Kotlin support and applies the Kotlin
+// plugin itself. Applying it a second time fails the configuration phase with
+// "Cannot add extension with name 'kotlin'". Apply it only when AGP is not
+// providing Kotlin: AGP 8 and older, or AGP 9 with android.builtInKotlin=false.
+def shouldApplyKotlinPlugin() {
+  def agpMajor = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION.tokenize('.')[0].toInteger()
+  if (agpMajor <= 8) {
+    return true
+  }
+  // AGP 10 removes the opt-out: built-in Kotlin is always active there.
+  if (agpMajor >= 10) {
+    return false
+  }
+  def propertyVal = providers.gradleProperty("android.builtInKotlin").orNull
+  def builtInKotlinEnabled = propertyVal != null ? propertyVal.toBoolean() : true
+  return !builtInKotlinEnabled
+}
+
+if (shouldApplyKotlinPlugin()) {
+  apply plugin: "kotlin-android"
+}
 
 if (isNewArchitectureEnabled()) {
   apply plugin: "com.facebook.react"

packages/plugin-session-replay-react-native/android/build.gradle

@@ -18,7 +18,27 @@ if (findProject(':app') != null) {
 }
 
 apply plugin: "com.android.library"
-apply plugin: "kotlin-android"
+// Android Gradle Plugin 9 ships built-in Kotlin support and applies the Kotlin
+// plugin itself. Applying it a second time fails the configuration phase with
+// "Cannot add extension with name 'kotlin'". Apply it only when AGP is not
+// providing Kotlin: AGP 8 and older, or AGP 9 with android.builtInKotlin=false.
+def shouldApplyKotlinPlugin() {
+  def agpMajor = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION.tokenize('.')[0].toInteger()
+  if (agpMajor <= 8) {
+    return true
+  }
+  // AGP 10 removes the opt-out: built-in Kotlin is always active there.
+  if (agpMajor >= 10) {
+    return false
+  }
+  def propertyVal = providers.gradleProperty("android.builtInKotlin").orNull
+  def builtInKotlinEnabled = propertyVal != null ? propertyVal.toBoolean() : true
+  return !builtInKotlinEnabled
+}
+
+if (shouldApplyKotlinPlugin()) {
+  apply plugin: "kotlin-android"
+}
 
 if (isNewArchitectureEnabled()) {
   apply plugin: "com.facebook.react"

packages/session-replay-react-native/android/build.gradle

@@ -18,7 +18,27 @@ if (findProject(':app') != null) {
 }
 
 apply plugin: "com.android.library"
-apply plugin: "kotlin-android"
+// Android Gradle Plugin 9 ships built-in Kotlin support and applies the Kotlin
+// plugin itself. Applying it a second time fails the configuration phase with
+// "Cannot add extension with name 'kotlin'". Apply it only when AGP is not
+// providing Kotlin: AGP 8 and older, or AGP 9 with android.builtInKotlin=false.
+def shouldApplyKotlinPlugin() {
+  def agpMajor = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION.tokenize('.')[0].toInteger()
+  if (agpMajor <= 8) {
+    return true
+  }
+  // AGP 10 removes the opt-out: built-in Kotlin is always active there.
+  if (agpMajor >= 10) {
+    return false
+  }
+  def propertyVal = providers.gradleProperty("android.builtInKotlin").orNull
+  def builtInKotlinEnabled = propertyVal != null ? propertyVal.toBoolean() : true
+  return !builtInKotlinEnabled
+}
+
+if (shouldApplyKotlinPlugin()) {
+  apply plugin: "kotlin-android"
+}
 
 if (isNewArchitectureEnabled()) {
   apply plugin: "com.facebook.react"