Fix snapshot of a host/device cc_library with stubs

Adds a test that fails with unknown property android.stubs.versions
and then fixes that by marking the field from which that property is
created with 'ignored-on-host' and implemented the isHostVariant on
*osTypeSpecificInfo.

Bug: 155628860
Test: m nothing
Change-Id: I167b47a1374f541aa09d7e045972d740f1d9009c