LeAudio: Fix not updating metadata on all the devices

Fixes a case when metadata was updated only at the first device within
the group.

Bug: 262230399
Tag: #feature
Test: atest --host StateMachineTest#testUpdateMetadataMultiple --no-bazel-mode
Change-Id: I492ac8805deb78501c195f163970bf508e25b5da
Merged-In: I492ac8805deb78501c195f163970bf508e25b5da
(cherry picked from commit c4ba6604)