Show error message for RuntimeExceptions.

Previously, all errors were assumed to be of the class
CommandException. This may not always be the case, for example if
a SIM card is missing. If it is not a CommandException, show a
generic error message in this case.

Bug: 21268151
Change-Id: I280971a65ab2ed8470499a74d91be1fb6ac331bf
2 files changed