Is your feature improvement request related to a problem? Please describe.

An upcoming Cumulocity change to the SmartREST 2.0 101 message will add support for creating child devices with the c8y_IsDevice fragment, which means the device can show up in the Cumulocity All Devices list.

New SmartREST 2.0 101 message example:

101,child_IsDevice_2,"child2 name",childType,<true|false>

Where the 5th column in the CSV controls whether the c8y_IsDevice fragment is to be added to the child device or not (for newly created child devices only). The options are as follows:

• true => Add the c8y_IsDevice fragment
• false => Don't add c8y_IsDevice (the current default behaviour)

The additional fragment can already be added to the outgoing 101 messages, because if Cumulocity does not support this new fields it will just ignore it (so no Cumulocity version/feature checking is required).

Describe the solution you'd like

The following changes are required

• Add new tedge.toml configuration to control whether child devices should have the 5th columns set to true or false. Default to true (this is the new default being adopted by other Cumulocity products).
• Add the 5th column, where the value is based on the new tedge.toml configuration, to all outgoing 101 Cumulocity SmartREST 2.0 messages (regardless of the Cumulocity version)

Describe alternatives you've considered

The following decisions were

• Controlling the c8y_IsDevice setting per child device is not required as it would lead to inconsistencies (why is child-device1 in the All Devices list, but child-device2 isn't). We can change this stance in the future if there is enough customer feedback, but for the moment we will favour fleet consistency over flexibility

Additional context