Add Swift bridge for BackHandlerView

Author: colemancda

Sources/AndroidSwiftUI/BackHandlerView.swift

@@ -0,0 +1,43 @@
+//
+//  BackHandlerView.swift
+//  AndroidSwiftUI
+//
+//  Created by Alsey Coleman Miller on 7/16/26.
+//
+
+import AndroidKit
+
+/// Hosts a Jetpack Compose `BackHandler` to intercept the system back button.
+@JavaClass("com.pureswift.swiftandroid.BackHandlerView")
+open class BackHandlerView: AndroidView.View {
+
+    @JavaMethod
+    @_nonoverride public convenience init(_ context: AndroidContent.Context?, _ callback: SwiftObject?, environment: JNIEnvironment? = nil)
+
+    @JavaMethod
+    public func getCallback() -> SwiftObject?
+
+    @JavaMethod
+    open func setBackHandlerEnabled(_ enabled: Bool)
+}
+
+@JavaImplementation("com.pureswift.swiftandroid.BackHandlerView")
+extension BackHandlerView {
+
+    @JavaMethod
+    func onBack() {
+        callback()
+    }
+}
+
+public extension BackHandlerView {
+
+    convenience init(_ context: AndroidContent.Context, environment: JNIEnvironment? = nil, action: @escaping () -> ()) {
+        let object = SwiftObject(action, environment: environment)
+        self.init(context, object, environment: environment)
+    }
+
+    var callback: (() -> ()) {
+        getCallback()!.valueObject().value as! (() -> ())
+    }
+}