Add ActivityTransitionInfo for activity tansition.

This change introduces the ActivityTransitionInfo object, which
encapsulates activity transition details within TransitionInfo. This new
object clarifies the task ID, pertains specifically to an activity. For
task transitions, TransitionInfo already includes a task ID in
mTaskInfo, so separating activity-specific information into
ActivityTransitionInfo prevents confusion and allows transition
observers to perform more precise checks based on the activity's task
ID.

Bug: 390047887
Flag: EXEMPT bug fix
Test: atest FrameworksCoreTests:ConfigurationChangeSettingTest
Test: atest FrameworksCoreTests:TransitionInfoTest
Test: atest PlatformAnimationLibCoreTests:OriginTransitionSessionTest
Test: atest WmTests:TransitionTests
Change-Id: Ie82abd0f9bcde63afea38d46f8ee9d8cc6e749a9