Allow user to finish typing date before formatting

Debounce `onExpirationChange` to avoid calling `formatDateToString`
on invalid on uncompletely inputed date strings.

Signed-off-by: fenn-cs <fenn25.fn@gmail.com>

apps/files_sharing/src/mixins/SharesMixin.js

@@ -221,10 +221,9 @@ export default {
 		 *
 		 * @param {Date} date
 		 */
-		onExpirationChange(date) {
+		onExpirationChange: debounce((date) => {
 			this.share.expireDate = this.formatDateToString(new Date(date))
-		},
-
+		}, 500),
 		/**
 		 * Uncheck expire date
 		 * We need this method because @update:checked