scripts: intended-roles: Use both device and stream

When a stream gets added, we might have a situation where the device
does not yet exist to actually link on the basis of intended role. For
example this can be observed if no mic sources are present and then the
mic appears after a bluetooth profile switch to HFP.

To fix this, iterate over streams when a device connects in addition to
iterating over devices when a stream connects.
7 jobs for media-role-bt-policy in 2 minutes and 30 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Container
passed container_fedora #15547485

00:01:00

passed container_ubuntu #15547486

00:00:47

 
  Build
passed build_on_fedora_no_docs #15547488

00:00:36

passed build_on_fedora_with_docs #15547487

00:00:41

passed build_on_ubuntu_no_gir #15547490

00:00:35

passed build_on_ubuntu_with_gir #15547489

00:00:39

 
  Analysis
passed shellcheck #15547491

00:00:49