refactor(storage): Refactor Java and Objc to Kotlin and Swift (#17795)

Author: MichaelVerdon

packages/firebase_storage/firebase_storage/android/build.gradle

@@ -5,10 +5,15 @@ apply plugin: 'com.android.library'
 apply from: file("local-config.gradle")
 
 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 {
@@ -39,6 +44,8 @@ def getRootProjectExtOrCoreProperty(name, firebaseCoreProject) {
     return rootProject.ext.get('FlutterFire').get(name)
 }
 
+apply plugin: 'kotlin-android'
+
 android {
     // Conditional for compatibility with AGP <4.2.
     if (project.android.hasProperty("namespace")) {
@@ -52,11 +59,20 @@ android {
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
 
+    kotlinOptions {
+        jvmTarget = project.ext.javaVersion
+    }
+
     compileOptions {
         sourceCompatibility project.ext.javaVersion
         targetCompatibility project.ext.javaVersion
     }
 
+    sourceSets {
+        main.java.srcDirs += "src/main/kotlin"
+        test.java.srcDirs += "src/test/kotlin"
+    }
+
     buildFeatures {
         buildConfig = true
     }