Fix undo when auto-advance is not set to 'list'

Auto-advance broke undo because undo did a sequence number check before
doing anything, and a side effect of auto-advance is to mark the next
conversation read!

Added more toString() logging to assist improve 'dumpsys activity'
output.

Bug: 8877688
Change-Id: I54597c4511780651a3a043a7752191cbad6fa1b9
5 files changed