Fixed #27996 -- Added RandomUUID function and CryptoExtension to contrib.postgres.

tests/postgres_tests/migrations/0002_create_test_models.py

@@ -191,6 +191,13 @@ class Migration(migrations.Migration):
                 ('when', models.DateTimeField(null=True, default=None)),
             ]
         ),
+        migrations.CreateModel(
+            name='UUIDTestModel',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('uuid', models.UUIDField(default=None, null=True)),
+            ]
+        ),
         migrations.CreateModel(
             name='RangesModel',
             fields=[