test: Add ES polyfills to external tests, so we can use methods like Array#from, Object#assign, etc.
test: Add ES polyfills to external tests, so we can use methods like Array#from, Object#assign, etc.

PiperOrigin-RevId: 322861630

material-components/material-components-web,material-components/material-components-web,material-components/material-components-web