Before this change we'd rely on new androidx OnBackPressedCallback mechanism. It turns out not to work well in a few cases. The biggest problem with it was that when registered it'd never allow for the hw back button press to fallback to a system default behaviour and instead would always "still" that event. After several attempts of trying to make it work I decided to revert back to a FragmentManager's default solution.
This change adds an ability to use FragmentManager's back stack API. There are also a few problems with it we need to workaround though. One of the problem is the fact that we can not modify back stack history. What we do because of that is that we try to keep at most one item on the back stack and reset it each time our native stack updates. In order for that to work we create a fake transaction that hides and shows the same screen that displays on top. Thanks to that when hw back is pressed the built in transaction rollback logic does nothing to the UI and allows us to handle back navigation using back stack change listener.
A few bugs fixed with android native stack in this commit:
- fixed a problem with views not resizing when keyboard appears, the bug was due to onMeasure forwardin getHeight which was the old height of the container instead of the changed one
- fixed a problem with back button behavior not being consistent. Now back button is controlled by 'gestureEnabled' to emulate iOS behavior where there is no hw back button but you can swipe back instead.
- added compatibility for "contained" modal styles - for now we always render "containted" fragments on Android, plan to add a way to render in dialogs in the future
* Let UINavController control subcontroller view's frames.
This PR changes the way we've been handling yoga <> NavController layout interactions. Now we ignore frame updates coming from react for the main Screen view to allow NavController take the controll. In order to keep yoga working we now use `setSize` to pass the dimensions of the view back to yoga such that it can properly calculate layout of the views under Screen component.
* Header resizing fixes for Android.
In this change we use CoordinatorLayout as a stack screen container to handle rendering of toolbar and screen content. Thanks to this approach we can support collapsable bars in the future. Instead of relying on RN to layout screen container when renered under ScreenStack we rely on Android native layout to measure and position screen content and then use UIManager.setNodeSize to communicate that back to react.
