[Test] Ensure no clashes with other timestamp registration tests.

spring-cloud-dataflow-shell-core/src/test/java/org/springframework/cloud/dataflow/shell/command/AppRegistryCommandsTests.java

@@ -100,7 +100,7 @@ private AppRegistration registerTimeSource(String name, String timeSourceArtifac
 	class AppRegisterTests {
 		@Test
 		void taskAppNoBootVersion() {
-			AppRegistration registration = registerTimestampTask("timestamp", "3.2.0", "", false);
+			AppRegistration registration = registerTimestampTask("timestamp1", "3.2.0", "", false);
 			assertThat(registration.getVersion()).isEqualTo("3.2.0");
 			assertThat(registration.getBootVersion()).isEqualTo(AppBootSchemaVersion.defaultVersion());
 		}