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
diff --git a/cc/library_sdk_member.go b/cc/library_sdk_member.go
index 730012c..a7a1de2 100644
--- a/cc/library_sdk_member.go
+++ b/cc/library_sdk_member.go
@@ -342,7 +342,11 @@
 
 	// The specific stubs version for the lib variant, or empty string if stubs
 	// are not in use.
-	StubsVersion string
+	//
+	// Marked 'ignored-on-host' as the StubsVersion() from which this is initialized is
+	// not set on host and the stubs.versions property which this is written to is does
+	// not vary by arch so cannot be android specific.
+	StubsVersion string `sdk:"ignored-on-host"`
 
 	// outputFile is not exported as it is always arch specific.
 	outputFile android.Path