[quick_actions] Switch to Kotlin Pigeon (#11507)

Replaces the Java Pigeon generator with the Kotlin Pigeon generator, and adjusts the project accordingly:
- Adds Kotlin build setings to Gradle.
- Updates API signatures for Kotlin/Java differences.
- Adds generic Java/Kotlin compat shim to create Result objects from Java, since those haven't been added to the Pigeon generator yet.

Part of flutter/flutter#158287

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: stuartmorgan-g

packages/quick_actions/quick_actions_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.0.30
+
+* Updates internal implementation to use Kotlin Pigeon.
+
 ## 1.0.29
 
 * Simplifies thread handling in message responses.

packages/quick_actions/quick_actions_android/android/build.gradle.kts

@@ -1,14 +1,18 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
 group = "io.flutter.plugins.quickactions"
 version = "1.0-SNAPSHOT"
 
 buildscript {
+    val kotlinVersion = "2.3.20"
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
         classpath("com.android.tools.build:gradle:8.13.1")
+        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion")
     }
 }
 
@@ -21,6 +25,13 @@ allprojects {
 
 plugins {
     id("com.android.library")
+    id("kotlin-android")
+}
+
+kotlin {
+    compilerOptions {
+        jvmTarget = JvmTarget.fromTarget(JavaVersion.VERSION_17.toString())
+    }
 }
 
 android {