## Introduction
Before we move container scheme to ready we need to have both the `colorScheme` and `typographyScheme` nonnull. By making colorScheme and typographyScheme of MDCContainerScheming nonnull, clients will reduce the amount of conditional checks required in their apps and reduce a category of potential errors (accidentally passing nil to a nonnull parameter).
## The problem
Both `colorScheme` and `typographyScheme` were nullable in the container scheme making it harder for clients to use the container scheme throughout their app on non Material UIElements, i.e. UIView.backgroundColor
## The fix
Make both of these properties nonnull.
## Additional work
- [x] I had to update the swift examples to not be optional and I additionally removed the nil checks from the ObjC examples.
## Related links
* Bug: #6438
* Component: [Dialogs](https://github.com/material-components/material-components-ios/tree/develop/components/Dialogs)
## Introduction
As we move to theming extensions all components that have a theming extension should use that within it's examples. Currently MDCAlertController has a theming extension and should use it in all examples. Additionally all components within the examples that have a theming extension should use it.
## The problem
Within MDCAlertController examples some components are using the old _Themers_.
## The fix
For all components being used in MDCAlertController examples use a theming extension if available.
## Additional notes
This also cleans up some ivar usage and import statements.
Adding two new rules to our bazel definitions for examples. Objective-C
examples and Swift examples. Using these ensures we have a common set of
definitions for things like warnings, Swift version, and default
visibility.
Closes#6215
This is an automated change generated by replacing all instances of MaterialComponentsAlpha with MaterialComponentsBeta. This is not a breaking change because changes to Alpha/Beta components (including renaming them) are not considered breaking.
The MaterialComponentsAlpha podspec was mistakenly named Alpha, when what we meant was more close to Beta. The distinction is that Alpha components are not expected to be used by clients, while Beta components are.
