Use preferred APN for IA if it'll work.

The old behavior would prefer the first IA APN over the
preferred APN even if the preferred APN listed IA.  Crazy!

Reworked ApnSetting.canHandleType to incorporate the "wildcard (*)
doesn't work for IA - that has to be explicitly listed" idea
and added tests for the function.

Test: added ApnSettingTest.testCanHandleType unit test
bug:31949444
Change-Id: I7d72dcbb3e068c2defcf4cfbc0c2a5a0f69f26b8