Add sensitive notification protection exemptions

- Add exemption for FGS notifications from the app that started
  projection
- Add exemption for single activity/task projection session

Bug: 316955208
Bug: 316955346
Test: atest SensitiveNotificationProtectionControllerTest
Flag: ACONFIG com.android.systemui.screenshare_notification_hiding DISABLED
Change-Id: I4dfb3af641f0ce6a89fa95e798cab9a63af96beb