Persistent repo on external display fix.

Removes the early return blocking repository initialization if internal
display does not support desktop; instead, if a desk would be
initialized to DEFAULT_DISPLAY on such a device, mark it as transient
instead.

Transient desks will be recorded in repository for preservation
purposes only; once preserved, the desk will be removed from the
repository, making sure not to inform any listeners along the way.

Bug: 437420625
Test: Manual
Flag: com.android.window.flags.enable_display_reconnect_interaction
Flag: com.android.window.flags.enable_external_display_persistence_bugfix
Change-Id: I96c904b407baa40eb6a370a8e45d3fa0dc5ab706