Replace RelPathString() with ToMakePath()

Add a ToMakePath() method that returns a new path that points out
out/ instead of out/soong/, and replace the
"$(OUT_DIR)/" + path.RelPathString()
pattern with
path.ToMakePath().String()

Bug: 141877526
Test: m checkbuild
Change-Id: I391b9f2ed78c83a58d905d48355ce9b01d610d16
diff --git a/android/prebuilt_etc.go b/android/prebuilt_etc.go
index 3aeda1c..6c4813b 100644
--- a/android/prebuilt_etc.go
+++ b/android/prebuilt_etc.go
@@ -158,7 +158,7 @@
 		ExtraEntries: []AndroidMkExtraEntriesFunc{
 			func(entries *AndroidMkEntries) {
 				entries.SetString("LOCAL_MODULE_TAGS", "optional")
-				entries.SetString("LOCAL_MODULE_PATH", "$(OUT_DIR)/"+p.installDirPath.RelPathString())
+				entries.SetString("LOCAL_MODULE_PATH", p.installDirPath.ToMakePath().String())
 				entries.SetString("LOCAL_INSTALLED_MODULE_STEM", p.outputFilePath.Base())
 				entries.SetString("LOCAL_UNINSTALLABLE_MODULE", strconv.FormatBool(!p.Installable()))
 				if p.additionalDependencies != nil {