Insecure permission: A normal user can escalate his/her role to admin

### Overview
There exists an **insecure permission** in BRCC from version **1.0.1** to latest. A normal user can escalate his/her role to admin via a POST request.

**The affected interface** is **/console/admin/updateAdmin/{userId}**.
This interface allows normal users to arbitrarily modify their own roles.

### Details
**Affected Function**: com.baidu.brcc.controller.AdminController#updateAdmin

The validation logic in the interface implementation:
1. Whether the user is in an available state.
2. Whether the user is an administrator; if not, it only needs to be verified whether they are modifying their own data.

The interface implementation did not validate whether non-administrator users could modify their own roles, thus allowing normal users to change their roles to administrator without any restrictions.

### Exploit

**test001** is a normal user, the code of role is 0.
**rcc-token** in the header of request is the token of **test001**.

It's successful. **test001** has become an administrator.

Start at com.baidu.brcc.controller.AdminController#updateAdmin and reproduce the POST request to /console/admin/updateAdmin/{userId} with a normal user's token. Trace the role-update validation and verify that a normal user cannot change their own role, while the intended administrator behavior remains available.

Written by the indexing model from the issue text.