spa: bluez: a2dp-source: set media.* keys based on the device's player

Find a spa_bt_player among the devices of the transport and
set a couple media.* node properties based on the player's data.
28 jobs for spa_bluez_follow_MediaPlayer1 in 2 minutes and 52 seconds (queued for 3 seconds)
latest
Status Name Job ID Coverage
  Container
passed container_fedora #11301476

00:00:25

passed container_ubuntu #11301475

00:00:20

 
  Build
passed build_on_fedora #11301478

00:01:29

passed build_on_ubuntu #11301477

00:00:57

passed build_with_custom_options: [audiotestsrc, disabled] #11301489

00:00:51

passed build_with_custom_options: [audiotestsrc, enabled] #11301488

00:01:34

passed build_with_custom_options: [bluez5-backend-hsphfpd, disabled] #11301487

00:00:42

passed build_with_custom_options: [bluez5-backend-hsphfpd, enabled] #11301486

00:00:52

passed build_with_custom_options: [docs, disabled] #11301481

00:00:56

passed build_with_custom_options: [docs, enabled] #11301480

00:01:24

passed build_with_custom_options: [installed_tests, disabled] #11301483

00:01:24

passed build_with_custom_options: [installed_tests, enabled] #11301482

00:01:24

passed build_with_custom_options: [sdl2, disabled] #11301499

00:00:50

passed build_with_custom_options: [sdl2, enabled] #11301498

00:01:35

passed build_with_custom_options: [sndfile, disabled] #11301501

00:00:43

passed build_with_custom_options: [sndfile, enabled] #11301500

00:01:34

passed build_with_custom_options: [systemd-system-service, disabled] #11301485

00:01:30

passed build_with_custom_options: [systemd-system-service, enabled] #11301484

00:00:52

passed build_with_custom_options: [test, disabled] #11301491

00:00:43

passed build_with_custom_options: [test, enabled] #11301490

00:01:37

passed build_with_custom_options: [videotestsrc, disabled] #11301493

00:00:50

passed build_with_custom_options: [videotestsrc, enabled] #11301492

00:01:36

passed build_with_custom_options: [volume, disabled] #11301495

00:01:36

passed build_with_custom_options: [volume, enabled] #11301494

00:00:43

passed build_with_custom_options: [vulkan, disabled] #11301497

00:00:44

passed build_with_custom_options: [vulkan, enabled] #11301496

00:00:50

passed build_with_no_commandline_options #11301479

00:00:56

 
  Analysis
passed shellcheck #11301502

00:00:43