Allow activity to be reparent while allowTaskReparenting is applied

Any malicious application could hijack tasks by
android:allowTaskReparenting. This vulnerability can perform UI
spoofing or spying on user’s activities.

This CL only allows activities to be reparent while
android:allowTaskReparenting is applied and the affinity of activity
is same with the target task.

Bug: 240663194
Test: atest IntentTests

Change-Id: I73abb9ec05af95bc14f887ae825a9ada9600f771