feat(mtls): Fix lint.

Author: andyrzhao

oauth2_http/java/com/google/auth/mtls/SecureConnectProvider.java

@@ -41,8 +41,8 @@
 import java.io.InputStream;
 import java.security.GeneralSecurityException;
 import java.security.KeyStore;
-import java.util.concurrent.TimeUnit;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 /**
  * This class implements {@link MtlsProvider} for the Google Auth library transport layer via {@link