test(ios): assert pending Google marker load applies the icon

groundAnchor is already set during apply. Asserting marker.icon
identity proves the deferred completion actually ran setIcon.

Author: jkasprzyk17

package/iosTests/GoogleMarkerVisualApplierTests.swift

@@ -24,8 +24,10 @@ final class GoogleMarkerVisualApplierTests: XCTestCase {
 
     XCTAssertEqual(completions.count, 1)
 
-    completions[0](makeIcon())
+    let icon = makeIcon()
+    completions[0](icon)
 
+    XCTAssertTrue(marker.icon === icon)
     XCTAssertEqual(marker.groundAnchor.x, 1, accuracy: 0.0001)
     XCTAssertEqual(marker.groundAnchor.y, 1, accuracy: 0.0001)
   }