AdminBarRemoval - change message/level for VIP Go

[rebeccahum]

Bug Description

For WordPressVIPMinimum.UserExperience.AdminBarRemoval.RemovalDetected in the WordPress-VIP-Go ruleset, we should downgrade it to a Warning level and change the error message to indicate that this should not be hidden for administrators and vip_support users only.

Minimal Code Snippet

if ( ! current_user_can( 'manage_options' ) ) {
	 	show_admin_bar( false );
}

Error Code

Error: Removal of admin bar is prohibited (WordPressVIPMinimum.UserExperience.AdminBarRemoval.RemovalDetected).

Tested Against master branch?

• I have verified the issue still exists in the master branch of VIPCS.