ci: Add tests for retry_delay trailer

Author: sakthivelmanii

google-cloud-spanner/src/test/java/com/google/cloud/spanner/ITTransactionRetryTest.java

@@ -0,0 +1,52 @@
+package com.google.cloud.spanner;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Assert;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@Category(ParallelIntegrationTest.class)
+@RunWith(JUnit4.class)
+public class ITTransactionRetryTest {
+
+  @ClassRule
+  public static IntegrationTestEnv env = new IntegrationTestEnv();
+
+  @Test
+  public void TestRetryInfo() {
+    // Creating a database with the table which contains INT64 columns
+    Database db = env.getTestHelper().createTestDatabase("CREATE TABLE Test(ID INT64, "
+        + "EMPID INT64) PRIMARY KEY (ID)");
+    DatabaseClient databaseClient = env.getTestHelper().getClient().getDatabaseClient(db.getId());
+
+    // Inserting one row
+    databaseClient.readWriteTransaction().run(transaction -> {
+      transaction.buffer(Mutation.newInsertBuilder("Test")
+              .set("ID")
+              .to(1)
+              .set("EMPID")
+              .to(1)
+          .build());
+      return null;
+    });
+
+    try(TransactionManager transactionManager1 = databaseClient.transactionManager()) {
+      try(TransactionManager transactionManager2 = databaseClient.transactionManager()) {
+        TransactionContext transaction1 = transactionManager1.begin();
+        TransactionContext transaction2 = transactionManager2.begin();
+        transaction1.executeUpdate(Statement.of("UPDATE Test SET EMPID = EMPID + 1 WHERE ID = 1"));
+        transaction2.executeUpdate(Statement.of("UPDATE Test SET EMPID = EMPID + 1 WHERE ID = 1"));
+        transactionManager1.commit();
+        AbortedException abortedException = Assert.assertThrows(AbortedException.class,
+            transactionManager2::commit);
+        assertThat(abortedException.getErrorCode()).isEqualTo(ErrorCode.ABORTED);
+        assertTrue(abortedException.getRetryDelayInMillis() > 0);
+      }
+    }
+  }
+}