Upgrade fonttools to 4.18.1 am: 13f9df0298 am: d6972fc726 am: 0869767a50

Original change: https://android-review.googlesource.com/c/platform/external/fonttools/+/1522558

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I5a35a08820ffd6b85166898050d186c0e78f1414