RANGER-5753: LDAP/Active Directory authentication does not validate local Ranger account status

[vyommani]

What changes were proposed in this pull request?

When Ranger Admin is configured for LDAP or Active Directory authentication
(ranger.authentication.method=LDAP or ACTIVE_DIRECTORY), RangerAuthenticationProvider
did not check the local Ranger account's status after a successful directory bind. This meant
a user's local account status could be out of sync with their actual ability to sign in when
directory-based authentication was used, unlike local/JDBC authentication, which already
respects account status via the STATUS column read by the JDBC user-details query.

This change adds a status check, UserMgr#isUserDisabled, and calls it from
RangerAuthenticationProvider#authenticate right after each successful LDAP, LDAP-bind,
AD-bind, AD, PAM, and UNIX authentication branch, before the method returns — so a disabled
local account is rejected consistently across all supported authentication methods.

How was this patch tested?

added new unit tests.

[mneethiraj]

isUserDisabled() method checks if the user status is "not active", which is different from disabled status. I suggest naming the method to isUserActive() and update all its references to handle the return value.

[mneethiraj]

@vyommani - I take back this comment. I will update here after further review.

[mneethiraj]

The method implementation checks if user is not active i.e., not explicitly if the user is disabled - note an user can be in one of other statuses like deactivated. So, I suggest:

• renaming isUserDisabled() to isUserNotActive()
• renaming checkAccountNotDisabled() to blockNotActiveUser()`

[mneethiraj]

I suggest renaming method checkAccountNotDisabled() to ensureUserIsActive(). Also, update the messages to replace "disabled" with "not active".