Fix batch metrics test

Micrometer's global registry might contain other metrics than
those from Spring Batch. This commit updates the test to expect
at least those from Spring Batch to be registered.

Issue BATCH-2774

spring-batch-samples/src/test/java/org/springframework/batch/sample/metrics/BatchMetricsTests.java

@@ -20,7 +20,6 @@
 
 import io.micrometer.core.instrument.Meter;
 import io.micrometer.core.instrument.Metrics;
-import org.hamcrest.Matchers;
 import org.junit.Test;
 
 import org.springframework.batch.core.ExitStatus;
@@ -42,11 +41,13 @@
 import org.springframework.context.annotation.Configuration;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 public class BatchMetricsTests {
 
+	private static final int EXPECTED_SPRING_BATCH_METRICS = 6;
+
 	@Test
 	public void testBatchMetrics() throws Exception {
 		// given
@@ -60,7 +61,7 @@ public void testBatchMetrics() throws Exception {
 		// then
 		assertEquals(ExitStatus.COMPLETED, jobExecution.getExitStatus());
 		List<Meter> meters = Metrics.globalRegistry.getMeters();
-		assertThat(meters, Matchers.hasSize(7));
+		assertTrue(meters.size() >= EXPECTED_SPRING_BATCH_METRICS);
 
 		try {
 			Metrics.globalRegistry.get("spring.batch.job")