Add more verbose logs for desktop-first factors

This CL adds more verbose logs for desktop-first decision factors, which
should make analyzing reports easier.

Note that this CL doesn't contain any functional change.

Fix: 406611707
Flag: com.android.window.flags.enable_display_windowing_mode_switching
Flag: com.android.window.flags.form_factor_based_desktop_first_switch
Test: build and logcat
Change-Id: I45d0f91d70f2067312510a66474ffb6fbc4485d9