pySim-shell: add ADF.ISIM / ADF.USIM dynamically

currently ADF.ISIM and ADF.USIM are always added regardless if there is
a matching application on the card or not. Lets check what applications
are actually installed and add ADF.ISIM and ADF.USIM dynamically.

Change-Id: I42ee23375f98e6322708c1c4db6d65e1425feecd
Related: OS#4963

pySim/cards.py

@@ -207,6 +207,7 @@ class Card(object):
 
 	# Fetch all the AIDs present on UICC
 	def read_aids(self):
+		self._aids = []
 		try:
 			# Find out how many records the EF.DIR has
 			# and store all the AIDs in the UICC
@@ -218,6 +219,8 @@ class Card(object):
 					self._aids.append(rec[0][8:8 + int(rec[0][6:8], 16) * 2])
 		except Exception as e:
 			print("Can't read AIDs from SIM -- %s" % (str(e),))
+			self._aids = []
+		return self._aids
 
 	# Select ADF.U/ISIM in the Card using its full AID
 	def select_adf_by_aid(self, adf="usim"):