Use varargs for DefaultApplicationArguments

Closes gh-15142

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/DefaultApplicationArguments.java

@@ -37,7 +37,7 @@ public class DefaultApplicationArguments implements ApplicationArguments {
 
 	private final String[] args;
 
-	public DefaultApplicationArguments(String[] args) {
+	public DefaultApplicationArguments(String... args) {
 		Assert.notNull(args, "Args must not be null");
 		this.source = new Source(args);
 		this.args = args;

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/DefaultApplicationArgumentsTests.java

@@ -80,8 +80,7 @@ public class DefaultApplicationArgumentsTests {
 
 	@Test
 	public void getNoNonOptionArgs() {
-		ApplicationArguments arguments = new DefaultApplicationArguments(
-				new String[] { "--debug" });
+		ApplicationArguments arguments = new DefaultApplicationArguments("--debug");
 		assertThat(arguments.getNonOptionArgs()).isEmpty();
 	}