fix(filepicker): Round previews in filepicker dialog

Signed-off-by: Jan C. Borchardt <925062+jancborchardt@users.noreply.github.com>

Author: jancborchardt

lib/components/FilePicker/FileListIcon.module.scss

@@ -14,6 +14,7 @@
 	min-height: 32px;
 	background-repeat: no-repeat;
 	background-size: contain;
+	border-radius: var(--border-radius-small);
 	// for the fallback
 	display: flex;
 	justify-content: center;