Use unique apex variations for bootclasspath fragments

Upcoming changes to the ApexInfo mutator will require unique apex
variations for the bootclasspath fragments, change them now to simplify
comparisons.

Test: go test ./...
Change-Id: Ia8880fe5ac22a7bd2fb9ddaeb3b04b9ae90b1701
diff --git a/apex/classpath_element_test.go b/apex/classpath_element_test.go
index f367174..55f1475 100644
--- a/apex/classpath_element_test.go
+++ b/apex/classpath_element_test.go
@@ -198,11 +198,11 @@
 
 	result := preparer.RunTest(t)
 
-	artFragment := result.Module("art-bootclasspath-fragment", "android_common_apex10000")
+	artFragment := result.Module("art-bootclasspath-fragment", "android_common_com.android.art")
 	artBaz := result.Module("baz", "android_common_apex10000")
 	artQuuz := result.Module("quuz", "android_common_apex10000")
 
-	myFragment := result.Module("mybootclasspath-fragment", "android_common_apex10000")
+	myFragment := result.Module("mybootclasspath-fragment", "android_common_myapex")
 	myBar := result.Module("bar", "android_common_apex10000")
 
 	other := result.Module("othersdklibrary", "android_common_apex10000")