Use OutputFilesProvider on syspropJavaGenRule

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: I3b1cb3a4cfafa1385ef27a427009abb13accf834
diff --git a/sysprop/sysprop_library.go b/sysprop/sysprop_library.go
index b9b68be..84f20c5 100644
--- a/sysprop/sysprop_library.go
+++ b/sysprop/sysprop_library.go
@@ -49,8 +49,6 @@
 	android.ModuleBase
 
 	properties syspropGenProperties
-
-	genSrcjars android.Paths
 }
 
 type syspropRustGenRule struct {
@@ -59,7 +57,6 @@
 	properties rustLibraryProperties
 }
 
-var _ android.OutputFileProducer = (*syspropJavaGenRule)(nil)
 var _ rust.SourceProvider = (*syspropRustGenRule)(nil)
 
 var (
@@ -100,6 +97,7 @@
 		}
 	})
 
+	var genSrcjars android.Paths
 	for _, syspropFile := range android.PathsForModuleSrc(ctx, g.properties.Srcs) {
 		srcJarFile := android.GenPathWithExt(ctx, "sysprop", syspropFile, "srcjar")
 
@@ -114,8 +112,10 @@
 			},
 		})
 
-		g.genSrcjars = append(g.genSrcjars, srcJarFile)
+		genSrcjars = append(genSrcjars, srcJarFile)
 	}
+
+	ctx.SetOutputFiles(genSrcjars, "")
 }
 
 func (g *syspropJavaGenRule) DepsMutator(ctx android.BottomUpMutatorContext) {
@@ -124,15 +124,6 @@
 	ctx.AddFarVariationDependencies(nil, nil, proptools.String(g.properties.Check_api))
 }
 
-func (g *syspropJavaGenRule) OutputFiles(tag string) (android.Paths, error) {
-	switch tag {
-	case "":
-		return g.genSrcjars, nil
-	default:
-		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
-	}
-}
-
 func syspropJavaGenFactory() android.Module {
 	g := &syspropJavaGenRule{}
 	g.AddProperties(&g.properties)