Use 0x15 for simulating disconnection

Author: chengweih001

index.bs

@@ -5543,7 +5543,7 @@ The [=remote end steps=] with command parameters |params| are:
     |simulatedDevice| inside |navigable|'s <a>active window</a>'s <a spec=HTML>associated <code>Navigator</code></a>'s
     [=associated Bluetooth=].
 1. If |simulatedDeviceInstance|.{{[[gatt]]}}.{{[[automatedGATTConnectionResponse]]}} is `"expected"`,
-    set |simulatedDeviceInstance|.{{[[gatt]]}}.{{[[automatedGATTConnectionResponse]]}} to `0x44`.
+    set |simulatedDeviceInstance|.{{[[gatt]]}}.{{[[automatedGATTConnectionResponse]]}} to `0x15`.
 1. Otherwise, <a>clean up the disconnected device</a> |simulatedDeviceInstance|.
 
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