fix(material/button): cdk-focus classes not being applied

[kevinjihwanlee]

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Fixes a bug in the Angular Material button component where cdk-focused, cdk-keyboard-focused, cdk-mouse-focused were not being applied upon respective focus. This is because there was no FocusManager set up with the MDC buttons like the legacy button did.

Fixes #25618

[crisbeto]

The code LGTM, but one of the CI checks is failing. You can run yarn approve-api button and commit the changed file to fix it.

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