cat: fix Supported Radio Access Technologies state flag

TS 102 223 8.105 codes each supported technology in two bytes:
- the technology from 8.61
- state byte, b1 0 disabled/1 enabled
- b2-b8 RFU

Currently declared as FlagsEnum(Int8ub, enabled=0). kw value is used as
bitmask, so currently:

build {'enabled': True}      -> b4 02 08 00     disabled
build {'enabled': False}     -> b4 02 08 00     disabled
but parsed 08 00 / 08 01 / 08 ff  -> all {'enabled': True}

Use the bit the spec names + tests because well this is so easy that we
don't need tests is apparently not the right approach here..

Change-Id: I4dd16182eb06c99265aabab5d889967b890f6bf2

pySim/cat.py

@@ -729,8 +729,12 @@ class DnsServerAddress(COMPR_TLV_IE, tag=0xC0):
 
 # TS 102 223 Section 8.105
 class SupportedRadioAccessTechnologies(COMPR_TLV_IE, tag=0xB4):
+    # 2 bytes/entry:
+    # - technology of 8.61
+    # - state byte b1 is 0 disabled/1 enabled
+    # - b2-b8 RFU.
     AccessTechTuple = Struct('technology'/AccessTechnology.SingleAccessTech,
-                             'state'/FlagsEnum(Int8ub, enabled=0))
+                             'state'/FlagsEnum(Int8ub, enabled=1))
     _construct = GreedyRange(AccessTechTuple)
 
 # TS 102 223 Section 8.107