Check for invalid simOperator.

The simOperator can either be null or empty string. Make sure the string
is long enough to split into MCC and MNC. Technically, a valid
simOperator can only be 5 or 6 digits, but we don't check explicitly for
those lengths to leave some flexibility in the code.

Bug: 20420802
Change-Id: Id8ac7f1e0d6866c5016f6b250d705ceb90626974
1 file changed