Fix source distribution LICENSE and NOTICE (#764)

Author: jbonofre

LICENSE

@@ -200,9 +200,14 @@
    See the License for the specific language governing permissions and
    limitations under the License.
 
-   This product bundles various third-party components also under the
-   Apache Software License 2.0.
+--------------------------------------------------------------------------------
 
-   Gradle (https://github.com/gradle/gradle)
-   ./gradlew
-   ./gradle/wrapper/gradle-wrapper.properties
+This product includes a gradle wrapper.
+
+* gradlew and gradle/wrapper/gradle-wrapper.properties
+
+Copyright: 2010-2019 Gradle Authors.
+Home page: https://github.com/gradle/gradle
+License: https://www.apache.org/licenses/LICENSE-2.0
+
+--------------------------------------------------------------------------------