Add whitespace after copyright header

Add an additional lines after the copyright header and before the
`package` declaration. This aligns with the style used by Spring
Framework.

Issue gh-8945

samples/xml/gae/src/main/java/samples/gae/security/AppRole.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.security;
 
 import org.springframework.security.core.GrantedAuthority;

samples/xml/gae/src/main/java/samples/gae/security/GaeAuthenticationFilter.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.security;
 
 import java.io.IOException;

samples/xml/gae/src/main/java/samples/gae/security/GaeUserAuthentication.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.security;
 
 import java.util.Collection;

samples/xml/gae/src/main/java/samples/gae/security/GoogleAccountsAuthenticationEntryPoint.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.security;
 
 import java.io.IOException;

samples/xml/gae/src/main/java/samples/gae/security/GoogleAccountsAuthenticationProvider.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.security;
 
 import com.google.appengine.api.users.User;

samples/xml/gae/src/main/java/samples/gae/users/GaeDatastoreUserRegistry.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.users;
 
 import com.google.appengine.api.datastore.DatastoreService;

samples/xml/gae/src/main/java/samples/gae/users/GaeUser.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.users;
 
 import java.io.Serializable;

samples/xml/gae/src/main/java/samples/gae/users/InMemoryUserRegistry.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.users;
 
 import java.util.Collections;

samples/xml/gae/src/main/java/samples/gae/users/UserRegistry.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.users;
 
 /**

samples/xml/gae/src/main/java/samples/gae/validation/Forename.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.validation;
 
 import static java.lang.annotation.ElementType.*;

samples/xml/gae/src/main/java/samples/gae/validation/ForenameValidator.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.validation;
 
 import java.util.regex.Pattern;

samples/xml/gae/src/main/java/samples/gae/validation/Surname.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.validation;
 
 import static java.lang.annotation.ElementType.*;

samples/xml/gae/src/main/java/samples/gae/validation/SurnameValidator.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.validation;
 
 import java.util.regex.Pattern;

samples/xml/gae/src/main/java/samples/gae/web/GaeAppController.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.web;
 
 import java.io.IOException;

samples/xml/gae/src/main/java/samples/gae/web/RegistrationController.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.web;
 
 import java.util.EnumSet;

samples/xml/gae/src/main/java/samples/gae/web/RegistrationForm.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.web;
 
 import samples.gae.validation.Forename;

samples/xml/gae/src/test/java/samples/gae/security/AppRoleTests.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.security;
 
 import static org.assertj.core.api.Assertions.*;

samples/xml/gae/src/test/java/samples/gae/users/GaeDataStoreUserRegistryTests.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package samples.gae.users;
 
 import static org.assertj.core.api.Assertions.assertThat;