Correctly handle activity starts from widgets in glanceable hub

Currently, widgets use the default starter logic which will just trigger
the activity underneath the keyguard if it is locked.

This change sets a custom interaction handler for widgets, which allows
us to customize how the intent is handled. This ensures we trigger the
bouncer if auth is required for the activity to launch.

This change intentionally doesn't tackle activity launch animations,
filed a follow-up bug to handle this.

Fixes: 317402992
Test: atest CommunalEditModeViewModelTest
Test: flashed device with changes and verified tapping stopwatch and
weather widgets correctly trigger the bouncer. Tapping widget which
launches a showWhenLocked activity does not trigger the bouncer.
Flag: ACONFIG com.android.systemui.communal_hub DEVELOPMENT

Change-Id: I3a9a2d57589088e356d46182f04f846cb19b346d