Make allow attribute configurable in iframe panel

src/panels/lovelace/cards/hui-iframe-card.ts

@@ -98,7 +98,7 @@ export class HuiIframeCard extends LitElement implements LovelaceCard {
             title=${ifDefined(this._config.title)}
             src=${this._config.url}
             .sandbox=${`${sandbox_user_params} ${IFRAME_SANDBOX}`}
-            allow="fullscreen"
+            allow=${this._config.allow ?? "fullscreen"}
           ></iframe>
         </div>
       </ha-card>

src/panels/lovelace/cards/types.ts

@@ -281,6 +281,7 @@ export interface IframeCardConfig extends LovelaceCardConfig {
   allow_open_top_navigation?: boolean;
   aspect_ratio?: string;
   title?: string;
+  allow?: string;
   url: string;
 }