Update accessibility policy to handle supervising profile as a child profile of any current user.

Context: When starting the supervising profile with talkback on, it
cannot recognize the keyboard as the userId does not belong the the same
profile of the current user.

Change-Id: I32e135e0eda71455a7b545e9d3aff98b3fb871ec
Bug: 430955186
Test: AccessibilitySecurityPolicyTest
Flag: android.multiuser.allow_supervising_profile