test(material/checkbox): refactor variable type to const in checkbox component unit tests (#22897)
test(material/checkbox): refactor variable type to const in checkbox component unit tests (#22897)


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