chore: sync changes for Maps JS API v3.56.8.

PiperOrigin-RevId: 623872500

Author: Closure Team

contrib/externs/maps/google_maps_api_v3_56.js

@@ -9309,7 +9309,7 @@ google.maps.Symbol = function() {};
  * anchor's x and y coordinates respectively. The position is expressed in
  * the same coordinate system as the symbol's path.
  * @default <code>google.maps.Point(0,0)</code>
- * @type {google.maps.Point|null|undefined}
+ * @type {!google.maps.Point|null|undefined}
  */
 google.maps.Symbol.prototype.anchor;
 
@@ -9334,7 +9334,7 @@ google.maps.Symbol.prototype.fillOpacity;
  * supplied by the marker. The origin is expressed in the same coordinate system
  * as the symbol&#39;s path. This property is unused for symbols on polylines.
  * @default <code>google.maps.Point(0,0)</code>
- * @type {google.maps.Point|null|undefined}
+ * @type {!google.maps.Point|null|undefined}
  */
 google.maps.Symbol.prototype.labelOrigin;
 

contrib/externs/maps/google_maps_api_v3_exp.js

@@ -9309,7 +9309,7 @@ google.maps.Symbol = function() {};
  * anchor's x and y coordinates respectively. The position is expressed in
  * the same coordinate system as the symbol's path.
  * @default <code>google.maps.Point(0,0)</code>
- * @type {google.maps.Point|null|undefined}
+ * @type {!google.maps.Point|null|undefined}
  */
 google.maps.Symbol.prototype.anchor;
 
@@ -9334,7 +9334,7 @@ google.maps.Symbol.prototype.fillOpacity;
  * supplied by the marker. The origin is expressed in the same coordinate system
  * as the symbol&#39;s path. This property is unused for symbols on polylines.
  * @default <code>google.maps.Point(0,0)</code>
- * @type {google.maps.Point|null|undefined}
+ * @type {!google.maps.Point|null|undefined}
  */
 google.maps.Symbol.prototype.labelOrigin;