This introduces a new, modern icon to be used for credit cards whose
type is unknown. It replaces the existing icon, but is the same size
and is semantically similar, so risk is low.

Known instances of this icon include both the "old" (canvas) and "new"
(native) Autofill dropdowns, and the PaymentRequest UI.

Bug: 768881
Change-Id: Ic19ee458d989a26e0bb222187284dafe0c4ea497
Reviewed-on: https://chromium-review.googlesource.com/1026049Reviewed-by: Cait Phillips <caitkp@chromium.org>
Reviewed-by: Mathieu Perreault <mathp@chromium.org>
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557182}