Make shading rule consistent between bookkeeper-server-shaded and bookkeeper-server-tests-shaded

[sijie]

Descriptions of the changes in this PR:

bookkeeper-server:test-jar is working with bookkeeper-server. we should make bookkeeper-server-tests-shaded work with bookkeeper-server-shaded. so this change is to make they have consistent shading rule.

<dependency>
      <groupId>org.apache.bookkeeper</groupId>
      <artifactId>bookkeeper-server-shaded</artifactId>
      <version>${bookkeeper.version}</version>
      <scope>test</scope>
    </dependency>
<dependency>
      <groupId>org.apache.bookkeeper</groupId>
      <artifactId>bookkeeper-server-tests-shaded</artifactId>
      <version>${bookkeeper.version}</version>
      <scope>test</scope>
    </dependency>

[merlimat]

👍