refactor(material/core): make typography normalization function private (#21286)
refactor(material/core): make typography normalization function private (#21286)

This was mistakenly made public in https://github.com/angular/components/pull/21059
DevVersion/material2,josephperrott/material2,angular/components,andrewseguin/material2,crisbeto/material2,DevVersion/material2,mmalerba/material2,crisbeto/material2,DevVersion/material2,andrewseguin/material2,crisbeto/material2,andrewseguin/material2,andrewseguin/material2,angular/components,andrewseguin/material2,angular/components,mmalerba/material2,DevVersion/material2,josephperrott/material2,josephperrott/material2,DevVersion/material2,mmalerba/material2,josephperrott/material2,mmalerba/material2,angular/components,mmalerba/material2,crisbeto/material2,josephperrott/material2