fix(material/core): typography-hierarchy mixin not exposed (#22752)
fix(material/core): typography-hierarchy mixin not exposed (#22752)

Fixes that the `typography-hierarchy` mixin wasn't exposed in the new theming index file.

Fixes #22737.
DevVersion/material2,DevVersion/material2,mmalerba/material2,mmalerba/material2,angular/components,angular/components,crisbeto/material2,DevVersion/material2,mmalerba/material2,josephperrott/material2,DevVersion/material2,crisbeto/material2,crisbeto/material2,angular/components,josephperrott/material2,josephperrott/material2,crisbeto/material2,angular/components,mmalerba/material2,josephperrott/material2,DevVersion/material2,mmalerba/material2,josephperrott/material2