Merge changes I505a7ad8,I92d88199 into main

* changes:
  Disable source apex variant using apex_available_name
  Skip `contents` validation of source bootclasspath fragments

android/apex.go

@@ -88,6 +88,9 @@ type ApexInfo struct {
 
 	// Returns the name of the overridden apex (com.android.foo)
 	BaseApexName string
+
+	// Returns the value of `apex_available_name`
+	ApexAvailableName string
 }
 
 // AllApexInfo holds the ApexInfo of all apexes that include this module.