Steps to Reproduce

Pls see the example project https://github.com/arok/test_image_picker

Prerequisites
Launch camera controller from secondary screen (route)

1. Launch the app and click on FAB in main screen, new PageRoute will push
2. Click on the button "Click me" and select "Camera" option in opened action sheet
3. In camera controller click on any place to get camera focus works
4. click cancel or make a photo

Actual result: the user navigates to the main screen
Expected result: the user should stay on the second page

As I understand the issue is that touch events throw down from CameraController to FlutterController when the user clicks in CameraController, after that action sheet hides and call of Navigator.pop() method pops secondary route.

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v1.4.9-hotfix.1, on Mac OS X 10.14.4 18E226, locale en-RU)
 
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[✓] iOS toolchain - develop for iOS devices (Xcode 10.2)
[✓] Android Studio (version 3.4)
[✓] IntelliJ IDEA Community Edition (version 2018.3.4)
[✓] Connected device (2 available)