Created typed class for the pin result

The initial goal was to remove PhoneConstants.  But in doing so, it made sense to replace
an int[] array as a return type with a strongly typed class called PinResult.

Bug: 147774309
Test: SystemUITests
Merged-In: I42f2141f9378fc4f7a6f11af6073d38f917528bc
Change-Id: I42f2141f9378fc4f7a6f11af6073d38f917528bc