Get rid of [now] superfluous HexAdapter

With the introduction of using osmocom.construct.{Bytes,GreedyBytes}
in Change-Id I1c8df6350c68aa408ec96ff6cd1e405ceb1a4fbb we don't have a
need for wrapping each instance of Bytes or GreedyBytes into a
HexAdapter anymore.  The osmocom.construct.{Bytes,GreedyBytes} will
automatically perform the related hex-string-to-bytes conversion if
needed - and during printing we have osmocom.utils.JsonEncoder that
makes sure to convert any bytes type to a hex-string.

Change-Id: I9c77e420c314f5e74458628dc4e767eab6d97123

pySim/cdma_ruim.py

@@ -115,7 +115,7 @@ class EF_AD(TransparentEF):
     '''3.4.33 Administrative Data'''
 
     _test_de_encode = [
-        ( "000000", { 'ms_operation_mode' : 'normal', 'additional_info' : '0000', 'rfu' : '' } ),
+        ( "000000", { 'ms_operation_mode' : 'normal', 'additional_info' : b'\x00\x00', 'rfu' : b'' } ),
     ]
     _test_no_pad = True
 
@@ -134,9 +134,9 @@ class EF_AD(TransparentEF):
             # Byte 1: Display Condition
             'ms_operation_mode'/Enum(Byte, self.OP_MODE),
             # Bytes 2-3: Additional information
-            'additional_info'/HexAdapter(Bytes(2)),
+            'additional_info'/Bytes(2),
             # Bytes 4..: RFU
-            'rfu'/HexAdapter(GreedyBytesRFU),
+            'rfu'/GreedyBytesRFU,
         )