Alert success icon should be a checkmark but is identical to error icon

[nickscialli-usds]

Description

The alert success icon is supposed to be a checkmark but is currently an exclamation point. It is identical to the icon for error alerts. See the Alert component site for the identical icons.

The icon was correct, but misaligned, as of this commit: https://github.com/uswds/uswds/blob/3eba7caf3c9abc5fb032b88a04c9c866bbb1c9dc/src/img/alerts/success.svg

But appears to have been inadvertently changed to the error icon during this commit: https://github.com/uswds/uswds/blob/9d431ceb5842e028b8a6c4ad3b996db00a70804b/src/img/alerts/success.svg

Steps to reproduce the issue

1. View alert icons at https://designsystem.digital.gov/components/alert/

Additional information

Incorrect success icon screenshot

[thisisdano]

Ugh, yuck. Thanks for pointing that out — i'll get that fixed asap.

[thisisdano]

Fixed in #3233

[nickscialli-usds]

Thank you!