Ensure default and remote transition handlers are first

- When Transitions migrated to ShellInit, the default/remote handlers
  got added after PipTransitionController (which should really also
  use ShellInit (to be fixed in a follow up CL)).  For now, we can
  be explicit about where they should be added in the list.

Bug: 241515409
Bug: 241484248
Test: atest PinnedStackTests
Test: atest WMShellFlickerTests:com.android.wm.shell.flicker.pip.AutoEnterPipOnGoToHomeTest
Change-Id: I696327004e06e7ddd402a509fa18c86c60b244d4