Use correct user context to get the EnhancedConfirmationManager

Bug: 357768060
Bug: 363074042
Test: Download Accessibility Scanner from play store, verified I can
turn on the a11y service as a second user
Test: atest AccessibilityManagerServiceTest
Flag: EXEMPT low risk bugfix

Change-Id: I6e01179ae4af791070a359ebf3a4d9e7b80f6575