BottomSheet at its default behavior allows clients to drag the bottom sheet downwards to dismiss it, and also allow it to be dismissed by tapping the scrim background when it is presented.
While there is an API to customize the behavior of tapping the scrim to not allow dismissal using dismissOnBackgroundTap. There is no way to customize the dragging behavior to not dismiss.
Therefore in this PR I have introduced a dismissOnDraggingDownSheet that does exactly that. It does so by returning NO in the gestureRecognizerShouldBegin if the MDCDraggableView if dismissOnDraggingDownSheet is set to NO.
Unit tests and documentation has been added along with the new API.
Closes#8457
This PR adds the shape theming API documentation using the doc generation script improvements that were added in PR #5463 .
To achieve this, I added into the .vars files of the supported components the missing variables, and ran the script `scripts/apply_all_templates`. Then I ran `scripts/generate_readme component` for the components that have been added the `shape-theming.md` file, so it is seen in the actual README.md of the component.
Specifically, Bottom Sheet was using the old method of documentation, and wasn't using the right generation method, so it's doc content was just copied to the right location to allow its generation to work well as well.
Closes#5319
