Do not log starting window removing if it's not part of a shell transition

A starting window can be shown outside of a transition, we shouldn't log the removing in that case because it's not part of shell's transition and will in fact lead to trace processing errors since the trace processor expects this data to have an associated and valid shell transition.

Bug: 416173046
Flag: EXEMPT minor bug fix
Change-Id: I0b4c0c721c27bf30062ea9109d06ecd5c0781965