Encapsulate AppCompat TaskInfo data

To better decouple letterbox logic from default core logic
we encapsulate TaskInfo property specific to app compat in
AppCompatTaskInfo.

Fix: 300802163
Test: atest WMShellUnitTests:ShellTaskOrganizerTests
Test: atest WMShellUnitTests:CompatUIControllerTest
Test: atest WMShellUnitTests:CompatUILayoutTest
Test: atest WMShellUnitTests:CompatUIWindowManagerTest
Test: atest WMShellUnitTests:LetterboxEduWindowManagerTest
Test: atest WMShellUnitTests:UserAspectRatioSettingsLayoutTest
Test: atest WMShellUnitTests:UserAspectRatioSettingsWindowManagerTest
Test: atest WmTests:ActivityRecordTests
Test: atest WmTests:WindowOrganizerTests
Test: atest WmTests:SizeCompatTests
Test: atest WmTests:TaskTests

Change-Id: I8beede6b98c2818898cd004d06e57abe2c99575f