Update CTS ConnectivityManager permissions tests to work with L release.

Removed getNetworkPreference() and setNetworkPreference() tests as
these functions are now fully deprecated and do nothing, including
performing no permissions checks.
Adjusted the arguments used to test startUsingNetworkFeature() to
make them more realistic as this function now performs some basic
argument checking before testing permissions.
Removed stopUsingNetworkFeature() test as this function can't
encounter permissions failures anymore.  It will only fail to find
a record of a matching startUsingNetworkFeature() call and return -1.

bug:17187446
bug:17187549
Change-Id: I14c310890c6905a9464d61113c2bfd789f290937