Use KeyguardStateController in GlobalActionsDialog

KeyguardStateController is the source of truth in SystemUI. In
particular, it is user aware and provides the state for the current
user.

Before this CL, GlobalActionsDialog used KeyguardManager in user 0,
which does not have the correct information for other users (unless we
used an unsupported API, that was not being used).

Test: manual, primary and secondary user
Fixes: 150146622
Change-Id: I5fd8786d403bed978443a8980950b66393c2b6ed