Update internal/orchestrator/bricks/testdata/my-app.source/app.yaml

Co-authored-by: Luca Rinaldi <l.rinaldi@arduino.cc>

Author: dido18

internal/orchestrator/bricks/testdata/my-app.source/app.yaml

@@ -1,6 +1,6 @@
 name: Copy of Blinking LED from Arduino Cloud
 description: Control the LED from the Arduino IoT Cloud using RPC calls
+icon: ☁️
 ports: []
 bricks:
-- arduino:arduino_cloud:
-icon: ☁️
+- arduino:arduino_cloud