fix(material-experimental/mdc-slider): skip resizing while the user is dragging (#25318)
fix(material-experimental/mdc-slider): skip resizing while the user is dragging (#25318)

Fixes an internal bug caused by #25288 where a slider was resizing while the user is dragging, causing the thumb to jump around.
angular/components,angular/components,angular/components,crisbeto/material2,crisbeto/material2,crisbeto/material2,angular/components,crisbeto/material2