cellular: fix creation of IMEI when reading device information

Signed-off-by: Tatiana Leon <Tatiana.Leon@digi.com>

Author: tatianaleon

digi/xbee/devices.py

@@ -6827,7 +6827,9 @@ def _read_device_info(self, reason, init=True, fire_event=True):
 
         # Generate the IMEI address.
         if init or self._imei_addr is None:
-            imei_addr = XBeeIMEIAddress(self._64bit_addr.address)
+            imei_val = str(self.get_parameter(ATStringCommand.IM, apply=False),
+                           encoding='utf8', errors='ignore')
+            imei_addr = XBeeIMEIAddress.from_string(imei_val)
             if self._imei_addr != imei_addr:
                 updated = True
                 self._imei_addr = imei_addr

digi/xbee/models/atcomm.py

@@ -77,6 +77,7 @@ class ATStringCommand(Enum):
     HP = ("HP", "Preamble ID")
     IC = ("IC", "Digital change detection")
     ID = ("ID", "Network PAN ID/Network ID/SSID")
+    IM = ("IM", "IMEI")
     IR = ("IR", "I/O sample rate")
     IS = ("IS", "Force sample")
     JN = ("JN", "Join notification")