feat(functions): add support for Pigeon. Update android to Kotlin.

packages/cloud_functions/analysis_options.yaml

@@ -0,0 +1,10 @@
+# Copyright 2025 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# in the LICENSE file.
+
+include: ../../analysis_options.yaml
+
+analyzer:
+  exclude:
+    - cloud_functions_platform_interface/lib/src/pigeon/messages.pigeon.dart
+    - cloud_functions_platform_interface/test/pigeon/test_api.dart

packages/cloud_functions/cloud_functions/android/build.gradle

@@ -3,12 +3,19 @@ version '1.0-SNAPSHOT'
 
 apply plugin: 'com.android.library'
 apply from: file("local-config.gradle")
+apply plugin: 'kotlin-android'
 
 buildscript {
+  ext.kotlin_version = "1.8.22"
   repositories {
     google()
     mavenCentral()
   }
+
+  dependencies {
+      classpath 'com.android.tools.build:gradle:8.1.4'
+      classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version")
+  }
 }
 
 rootProject.allprojects {
@@ -48,7 +55,12 @@ android {
       sourceCompatibility project.ext.javaVersion
       targetCompatibility project.ext.javaVersion
   }
-
+
+  sourceSets {
+    main.java.srcDirs += "src/main/kotlin"
+    test.java.srcDirs += "src/test/kotlin"
+  }
+
   buildFeatures {
     buildConfig = true
   }
@@ -64,6 +76,12 @@ android {
     implementation 'androidx.annotation:annotation:1.7.0'
     implementation 'org.reactivestreams:reactive-streams:1.0.4'
   }
+
+  kotlinOptions {
+    jvmTarget = JavaVersion.VERSION_17
+  }
+
 }
 
 apply from: file("./user-agent.gradle")
+apply plugin: 'org.jetbrains.kotlin.android'