Fix the sample sparklr2 start error.

Add ` @Qualifier("consumerTokenServices") ` to fix the start error.

```java
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'adminController' defined in class path resource [org/springframework/security/oauth/examples/sparklr/config/WebMvcConfig.class]: Unsatisfied dependency expressed through constructor argument with index 1 of type [org.springframework.security.oauth2.provider.token.ConsumerTokenServices]: : No qualifying bean of type [org.springframework.security.oauth2.provider.token.ConsumerTokenServices] is defined: expected single matching bean but found 2: consumerTokenServices,defaultAuthorizationServerTokenServices; 
```