Close the Notification Shade when starting/sharing traces.

This makes the UI look smoother and more polished. Attached to this
commit is a small change to remove the notification once the traces have
been shared since they are deleted immediately afterwards inside the
Traceur code anyways.

Bug: 305049544
Flag: ACONFIG record_issue_qs_tile DEVELOPMENT
Test: Tested this locally on a device.
Change-Id: I5e9b4ece86effb833e690ed65e62e567ba8d89e2