Update HtmlUnitDriver tests to align with HtmlUnit 2.26

See gh-8853 and cb34189c66

spring-boot-test/src/test/java/org/springframework/boot/test/web/htmlunit/webdriver/LocalHostWebConnectionHtmlUnitDriverTests.java

@@ -87,7 +87,8 @@ public class LocalHostWebConnectionHtmlUnitDriverTests {
 		this.thrown.expect(IllegalArgumentException.class);
 		this.thrown.expectMessage("Environment must not be null");
 		Capabilities capabilities = mock(Capabilities.class);
-		given(capabilities.getBrowserName()).willReturn("chrome");
+		given(capabilities.getBrowserName()).willReturn("htmlunit");
+		given(capabilities.getVersion()).willReturn("chrome");
 		new LocalHostWebConnectionHtmlUnitDriver(null, capabilities);
 	}