Improve logging in ScrollCaptureFrameworkSmokeTest

In the event of failure, this change prints some
very useful information such as, why no connection
was returned and potentially the name of the window
which was investigated.

Bug: 184117155
Test: atest ScrollCaptureFrameworkSmokeTest
Change-Id: Iecf5ef2d22d00773a08d0b2605391a4db0be9b21