Use OutputFilesProvider on prebuilt_apex and apex_set

In the context of incremental soong, the output files
inter-module-communication will be through OutputFilesProvider.
The OutputFileProducer interface will be deprecated.

Test: CI
Bug: 339477385
Change-Id: I5cb79a2e39f7fdd791762bcde5a5bfb325985274
diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 9ad5159..cf1d6a4 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -587,15 +587,6 @@
 	return false
 }
 
-func (p *Prebuilt) OutputFiles(tag string) (android.Paths, error) {
-	switch tag {
-	case "":
-		return android.Paths{p.outputApex}, nil
-	default:
-		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
-	}
-}
-
 // prebuilt_apex imports an `.apex` file into the build graph as if it was built with apex.
 func PrebuiltFactory() android.Module {
 	module := &Prebuilt{}
@@ -894,6 +885,8 @@
 		p.installedFile = ctx.InstallFile(p.installDir, p.installFilename, p.inputApex, p.compatSymlinks...)
 		p.provenanceMetaDataFile = provenance.GenerateArtifactProvenanceMetaData(ctx, p.inputApex, p.installedFile)
 	}
+
+	ctx.SetOutputFiles(android.Paths{p.outputApex}, "")
 }
 
 func (p *Prebuilt) ProvenanceMetaDataFile() android.OutputPath {
@@ -1009,15 +1002,6 @@
 	return false
 }
 
-func (a *ApexSet) OutputFiles(tag string) (android.Paths, error) {
-	switch tag {
-	case "":
-		return android.Paths{a.outputApex}, nil
-	default:
-		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
-	}
-}
-
 // prebuilt_apex imports an `.apex` file into the build graph as if it was built with apex.
 func apexSetFactory() android.Module {
 	module := &ApexSet{}
@@ -1121,6 +1105,8 @@
 	for _, overridden := range a.prebuiltCommonProperties.Overrides {
 		a.compatSymlinks = append(a.compatSymlinks, makeCompatSymlinks(overridden, ctx)...)
 	}
+
+	ctx.SetOutputFiles(android.Paths{a.outputApex}, "")
 }
 
 type systemExtContext struct {