samples: cellular: modem_shell: Make cJSON use system heap with CoAP

Make nRF Cloud and cJSON libraries use system heap instead of kernel
heap also with CoAP transport. This is needed to avoid running out
of memory in some use cases.

MOSH-596

Signed-off-by: Tommi Kangas <[email protected]>

Author: tokangas

samples/cellular/modem_shell/src/main.c

@@ -259,7 +259,8 @@ int main(void)
 
 	mosh_print_version_info();
 
-#if defined(CONFIG_NRF_CLOUD_REST) || defined(CONFIG_NRF_CLOUD_MQTT)
+#if defined(CONFIG_NRF_CLOUD_REST) || defined(CONFIG_NRF_CLOUD_MQTT) || \
+	defined(CONFIG_NRF_CLOUD_COAP)
 #if defined(CONFIG_MOSH_IPERF3)
 	/* Due to iperf3, we cannot let nrf cloud lib to initialize cJSON lib to be
 	 * using kernel heap allocations (i.e. k_ prepending functions).