Polish use getBeanProvider instead of getBeanNamesForType and getBean

[kse-music]

1. Use getBeanProvider instead of the similar code below

    if (this.context.getBeanNamesForType(A.class).length > 0) {
        this.bearerTokenResolver = this.context.getBean(A.class);
    }
    else {
        this.bearerTokenResolver = new A();
    }

2. In addition, also can avoid run error when define multiple Bean in contexts