le_audio: Extend handling of Broadcaster as active device

Patch extends handling Broadcaster as active Bluetooth device.
Broadcast device.

Bug: 150670922
Tag: #feature
Test: PTS and presubmit
Sponsor: jpawlowski@
Merged-In: Ic41c619411f1784bf586aa48ad0fa4a39a37ecb7
Change-Id: Ic41c619411f1784bf586aa48ad0fa4a39a37ecb7
(cherry picked from commit 7c1bf84c)