This article was originally published online on 8 June 2021 with a typographical error throughout. “Facial mask” was incorrectly typed as “facile mask.” Also “a constant” was typed as “aconstant” in the paragraph below Eq. (6). AIP Publishing apologizes for this error. All online versions of the article were corrected on 29 July 2021; the article is correct as it appears in the printed version of the journal.