tests: Bluetooth: CAP: Update unicast audio start unittests

Update the CAP initiator audio start unittest.
The reason for this, is that the recent change to endpoints
means that we need to properly generate a BAP unicast group
and call bt_bap_stream_config, instead of trying to manage
the bap_iso values directly.

As part of updating this, the tests were also updated to
significantly reduce code duplication, but generating
a default start param that can easily be reused.

Signed-off-by: Emil Gydesen <[email protected]>

Author: Thalley

tests/bluetooth/audio/cap_initiator/src/test_common.c

@@ -48,6 +48,7 @@ void test_unicast_set_state(struct bt_cap_stream *cap_stream, struct bt_conn *co
 			    enum bt_bap_ep_state state)
 {
 	struct bt_bap_stream *bap_stream = &cap_stream->bap_stream;
+	int err;
 
 	printk("Setting stream %p to state %d\n", bap_stream, state);
 
@@ -60,6 +61,9 @@ void test_unicast_set_state(struct bt_cap_stream *cap_stream, struct bt_conn *co
 	zassert_not_null(ep);
 	zassert_not_null(preset);
 
+	err = bt_bap_stream_config(conn, &cap_stream->bap_stream, ep, &preset->codec_cfg);
+	zassert_equal(err, 0, "Unexpected return value %d", err);
+
 	bap_stream->conn = conn;
 	bap_stream->ep = ep;
 	bap_stream->qos = &preset->qos;