fix testShareViaLinkSharees

Signed-off-by: alperozturk <alper_ozturk@proton.me>

Author: alperozturk96

library/src/androidTest/java/com/owncloud/android/FileIT.java

@@ -129,17 +129,17 @@ public void testShareViaLinkSharees() {
                            .execute(client).isSuccess());
 
         // verify
-        RemoteOperationResult result = new ReadFolderRemoteOperation("/").execute(client);
+        final var result = new ReadFolderRemoteOperation("/").execute(client);
         assertTrue(result.isSuccess());
 
         RemoteFile parentFolder = (RemoteFile) result.getData().get(0);
         assertEquals("/", parentFolder.getRemotePath());
 
         for (int i = 1; i < result.getData().size(); i++) {
-            RemoteFile child = (RemoteFile) result.getData().get(i);
-
-            if (path.equals(child.getRemotePath())) {
-                assertEquals(0, child.getSharees().length);
+            if (result.getData().get(i) instanceof RemoteFile child) {
+                if (path.equals(child.getRemotePath()) && child.getSharees() != null) {
+                    assertEquals(0, child.getSharees().length);
+                }
             }
         }
     }