Remove matching taskId check from getTaskScreenshots.

To keep multi-instance functionality consistent with taskbar, remove the matching taskId check so Manage Windows will show a screenshot for the task that called it. Ensure that nothing is done if it is clicked on.

Bug: 416911628
Test: Manual; open multi-instance supported app, launch multiple windows then Manage Windows, confirm requesting instance appears in screenshots
Flag: com.android.window.flags.enable_desktop_windowing_multi_instance_features
Change-Id: I34a4edf031888b7f399cd62f037d0ea58105f88e