update rust_builder

rust_builder/android/.gitignore

@@ -0,0 +1,9 @@
+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build
+/captures
+.cxx

rust_builder/android/build.gradle

@@ -0,0 +1,56 @@
+// The Android Gradle Plugin builds the native code with the Android NDK.
+
+group 'com.flutter_rust_bridge.rust_builder'
+version '1.0'
+
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+
+    dependencies {
+        // The Android Gradle Plugin knows how to build native code with the NDK.
+        classpath 'com.android.tools.build:gradle:7.3.0'
+    }
+}
+
+rootProject.allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+apply plugin: 'com.android.library'
+
+android {
+    if (project.android.hasProperty("namespace")) {
+        namespace 'com.flutter_rust_bridge.rust_builder'
+    }
+
+    // Bumping the plugin compileSdkVersion requires all clients of this plugin
+    // to bump the version in their app.
+    compileSdkVersion 33
+
+    // Use the NDK version
+    // declared in /android/app/build.gradle file of the Flutter project.
+    // Replace it with a version number if this plugin requires a specfic NDK version.
+    // (e.g. ndkVersion "23.1.7779620")
+    ndkVersion android.ndkVersion
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    defaultConfig {
+        minSdkVersion 19
+    }
+}
+
+apply from: "../cargokit/gradle/plugin.gradle"
+cargokit {
+    manifestDir = "../../rust"
+    libname = "rust"
+}

rust_builder/android/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'rust_builder'

rust_builder/android/src/main/AndroidManifest.xml

@@ -0,0 +1,3 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="com.flutter_rust_bridge.rust_builder">
+</manifest>