Refactor A11yManagerService#getAccessibilityShortcutTargets to require a userId

Existing function is deprecated and will be removed when all calls are replaced

Bug: 393626471
Test: atest AccessibilityManagerServiceTest AccessibilityShortcutControllerTest
Flag: com.android.server.accessibility.manager_lifecycle_user_change
Change-Id: I3ed340db006504141861aeecde7b382bf1c0958e