Added AuthConfigTest class

Signed-off-by: Marcos_Gonzalez_Mayedo <alemayed@amazon.com>

data-prepper-plugins/cwl-sink/src/main/java/org/opensearch/dataprepper/plugins/sink/AuthConfig.java

@@ -9,11 +9,11 @@
 public class AuthConfig {
     @JsonProperty("region")
     @NotEmpty
-    private String region = "";
+    private String region = "default";
 
     @JsonProperty("role_arn")
     @NotEmpty
-    private String role_arn = "";
+    private String role_arn = "default";
 
     public String getRegion() {
         return region;

data-prepper-plugins/cwl-sink/src/test/java/org/opensearch/dataprepper/plugins/sink/configuration/AuthConfigTest.java

@@ -0,0 +1,19 @@
+package org.opensearch.dataprepper.plugins.sink.configuration;
+
+import org.junit.jupiter.api.Test;
+import org.opensearch.dataprepper.plugins.sink.AuthConfig;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+public class AuthConfigTest {
+    @Test
+    void check_default_region_test() {
+        assertThat(new AuthConfig().getRegion(), equalTo("default"));
+    }
+
+    @Test
+    void check_default_role_test() {
+        assertThat(new AuthConfig().getRole_arn(), equalTo("default"));
+    }
+}