Add more logs to investigate disappearing home button

This will check when bouncer is hiding and what binders are held to
prevent flags from showing the home button. Seems that after keyguard
decides to hide itself and passes no disabled flags, something might be
preventing it from setting the statusbar flags.

Bug: 113914868
Test: manual
Change-Id: I9d1aeeedfbb840a770331a7020d3ba1abb20f5c9