Prevent double attempt to connect mesh api

Socket network interface tests were failing due to DICONNECTED event
being advertised, where GLOBAL_UP was expected. It turned out that
nanostack receives two events: APPL_EVENT_CONNECT and
APPL_BACKHAUL_INTERFACE_PHY_UP. The second attempt to connect obviously
returns errors, but it also causes events to be sent out to the
application. The second attempt should not take place in case the
bootstrap is already started.

I also fixed two reports being sent with DISCONNECT status, while they
are actually something else.

features/nanostack/mbed-mesh-api/source/ethernet_tasklet.c

@@ -120,7 +120,8 @@ void enet_tasklet_main(arm_event_s *event)
         case APPLICATION_EVENT:
             if (event->event_id == APPL_EVENT_CONNECT) {
                 enet_tasklet_configure_and_connect_to_network();
-            } else if (event->event_id == APPL_BACKHAUL_INTERFACE_PHY_UP) {
+            } else if (event->event_id == APPL_BACKHAUL_INTERFACE_PHY_UP
+                       && tasklet_data_ptr->tasklet_state != TASKLET_STATE_BOOTSTRAP_STARTED) {
                 // Ethernet cable has been plugged in
                 arm_nwk_interface_configure_ipv6_bootstrap_set(
                     tasklet_data_ptr->network_interface_id, NET_IPV6_BOOTSTRAP_AUTONOMOUS, NULL);
@@ -175,13 +176,13 @@ void enet_tasklet_parse_network_event(arm_event_s *event)
             /* No ND Router at current Channel Stack is Already at Idle state */
             tr_info("Bootstrap fail");
             tasklet_data_ptr->tasklet_state = TASKLET_STATE_BOOTSTRAP_FAILED;
-            enet_tasklet_network_state_changed(MESH_DISCONNECTED);
+            enet_tasklet_network_state_changed(MESH_BOOTSTRAP_FAILED);
             break;
         case ARM_NWK_NWK_CONNECTION_DOWN:
             /* Connection to Access point is lost wait for Scan Result */
             tr_info("Connection lost");
             tasklet_data_ptr->tasklet_state = TASKLET_STATE_BOOTSTRAP_FAILED;
-            enet_tasklet_network_state_changed(MESH_DISCONNECTED);
+            enet_tasklet_network_state_changed(MESH_BOOTSTRAP_FAILED);
             break;
         default:
             tr_warn("Unknown event %d", status);