Pop modal stack on back press

AndroidE2E/app/src/androidTest/java/com/reactnativenavigation/e2e/androide2e/ModalsTest.java

     public void pushIntoModal() throws Exception {
         elementByText("SHOW MODAL").click();
         elementByText("PUSH SCREEN").click();
-        assertExists(By.text("Pushed from modal"));
+        assertExists(By.text("Pushed Screen"));
+    }
+
+    @Test
+    public void backPopsModalStack() throws Exception {
+        elementByText("SHOW MODAL").click();
+        elementByText("PUSH SCREEN").click();
+        elementByText("PUSH").click();
+        device().pressBack();
+        assertExists(By.text("Pushed Screen"));
     }
 }

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/ModalStack.java

 package com.reactnativenavigation.viewcontrollers;
 
 import android.app.Dialog;
+import android.content.DialogInterface;
 import android.support.annotation.Nullable;
+import android.view.KeyEvent;
 import android.view.View;
 
 import com.facebook.react.bridge.Promise;
         return modal != null ? modal.viewController : null;
     }
 
-    private static class Modal {
+    private static class Modal implements DialogInterface.OnKeyListener {
 		public final ViewController viewController;
 		private final Dialog dialog;
 
 		Modal(final ViewController viewController) {
 			this.viewController = viewController;
 			dialog = new Dialog(viewController.getActivity(), R.style.Modal);
+			dialog.setOnKeyListener(this);
 		}
 
 		void show() {
 			View decorView = viewController.getActivity().getWindow().getDecorView();
 			viewController.getView().measure(makeMeasureSpec(decorView.getMeasuredWidth(), EXACTLY), makeMeasureSpec(decorView.getMeasuredHeight(), EXACTLY));
 		}
-	}
+
+        @Override
+        public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
+            if (keyCode == KeyEvent.KEYCODE_BACK) {
+                if (event.getAction() == KeyEvent.ACTION_UP) {
+                    if (viewController.handleBack()) {
+                        return true;
+                    }
+                    dialog.dismiss();
+                }
+            }
+            return false;
+        }
+    }
 }

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/Navigator.java

 	@NonNull
 	@Override
 	public Collection<ViewController> getChildControllers() {
-		return root == null ? Collections.<ViewController>emptyList() : Collections.singletonList(root);
+		return root == null ? Collections.emptyList() : Collections.singletonList(root);
 	}
 
 	@Override

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/NavigatorTest.java

 		StackController stack2 = newStack();
 		stack1.push(child1);
 		stack2.push(child2);
-		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
+		bottomTabsController.setTabs(Arrays.asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
 		SimpleViewController newChild = new SimpleViewController(activity, "new child");
 		stack2.push(child2);
 		stack2.push(child3);
 		stack2.push(child4);
-		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
+		bottomTabsController.setTabs(Arrays.asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
 		uut.pop("child4");
 		stack2.push(child2);
 		stack2.push(child3);
 		stack2.push(child4);
-		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
+		bottomTabsController.setTabs(Arrays.asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
 		uut.popSpecific(child2.getId());
 		stack2.push(child3);
 		stack2.push(child4);
 		stack2.push(child5);
-		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
+		bottomTabsController.setTabs(Arrays.asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
 		uut.popTo(child2.getId());
 		stack2.push(child4);
 		stack2.push(child5);
 
-		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
+		bottomTabsController.setTabs(Arrays.asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
 		uut.popToRoot(child3.getId());
 		stack2.push(child2);
 		stack2.push(child3);
 		stack2.push(child4);
-		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
+		bottomTabsController.setTabs(Arrays.asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
 		uut.pop("child4", new MockPromise() {

playground/src/containers/ModalScreen.js

 
   onClickPushScreen() {
     Navigation.push(this.props.containerId, {
-      name: `navigation.playground.TextScreen`,
+      name: `navigation.playground.PushedScreen`,
       passProps: {
         text: 'Pushed from modal'
       }