release: copy 12.0.0 changelog to master (#22683)
release: copy 12.0.0 changelog to master (#22683)


crisbeto/material2,mmalerba/material2,crisbeto/material2,DevVersion/material2,josephperrott/material2,DevVersion/material2,josephperrott/material2,mmalerba/material2,mmalerba/material2,angular/components,crisbeto/material2,crisbeto/material2,DevVersion/material2,DevVersion/material2,josephperrott/material2,angular/components,mmalerba/material2,DevVersion/material2,angular/components,josephperrott/material2,angular/components,josephperrott/material2,mmalerba/material2