4230 [camera_web] Handle camera errors in takePicture (cla: yes, waiting for tree to go green, p: camera, platform-web)

4231 Move test packages from dependencies to dev_dependencies (cla: yes, waiting for tree to go green, p: in_app_purchase, p: video_player, platform-ios, platform-android)

4232 Eliminate build_all_plugins_app.sh (cla: yes)

4234 [camera_web] Fix getCapabilities not supported error thrown when selecting a camera on Firefox (cla: yes, p: camera, platform-web)

4235 [camera_web] Add missing setFlashMode test (cla: yes, p: camera, platform-web)

4236 [camera] Fix a disposed CameraController error thrown when changing a camera (cla: yes, waiting for tree to go green, p: camera)