* [TabBar] Fixes for Safe Area insets.
* [TabBar] Check bar position.
* [TabBar] Add back intrinsicContentSize for consistency with sizeThatFits.
* [TabBar] RTL fixes
* [TabBar] Call setNeedsUpdateConstraints to match UIKit.
* [TabBar] Remove need for maintaining a height constraint for auto layout.
* [TabBar] Undo sizeThatFits/intrinsicContentSize changes.
* [TabBar] Revert more things.
* [TabBar] Undo more stuff.
* [TabBar] Review
The Bottom Navigation example for Tabs was overlapping with the Home Screen
indicator on the iPhone X. The example will now use safeAreaInsets if available
to calculate the position of the tab bar.
Closes#1975
All examples now have at least the required `+catalogBreadcrumbs` and `+catalogIsPrimaryDemo`. All examples in the same breadcrumbs path have only one primary demo. There should be only one `-catalogDescription` attached to the primary demo.
Closes#1897
