refactor: use getPaths() instead of getBaseDir()

getPaths() now supports filegroup/genrule/etc and returns src paths
which consist of "basedir + rel".

Bug: 189288369
Test: m
Change-Id: I9af0fe23b4c334d947c5d51c432acfaf2e0cdeb5
diff --git a/build/aidl_api.go b/build/aidl_api.go
index 3810d20..dc10814 100644
--- a/build/aidl_api.go
+++ b/build/aidl_api.go
@@ -107,11 +107,8 @@
 	var hashFile android.WritablePath
 
 	apiDir = android.PathForModuleOut(ctx, "dump")
-	aidlRoot := android.PathForModuleSrc(ctx, m.properties.AidlRoot)
 	for _, src := range srcs {
-		baseDir := getBaseDir(ctx, src, aidlRoot)
-		relPath, _ := filepath.Rel(baseDir, src.String())
-		outFile := android.PathForModuleOut(ctx, "dump", relPath)
+		outFile := android.PathForModuleOut(ctx, "dump", src.Rel())
 		apiFiles = append(apiFiles, outFile)
 	}
 	hashFile = android.PathForModuleOut(ctx, "dump", ".hash")