[CrOS Bluetooth] Add device status notification logs

This change adds Bluetooth logs to device status notifier to capture
when a notification is being created for Bluetooth device state
changes. This is to help debug issues where the notification is
not being shown.

Bug: b/345240570, b/339459005
Test: N/A
Change-Id: I3c64450a9333724328474827916ffc1a35d21f9d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5617313
Commit-Queue: Theo Johnson-kanu <tjohnsonkanu@google.com>
Reviewed-by: Gordon Seto <gordonseto@google.com>
Cr-Commit-Position: refs/heads/main@{#1313036}