soong_ui: Do not clean the OutDir path multiple times.

If OUT_DIR has been specified through the command line arguments,
it is sanitized first and NewConfig sets the OUT_DIR in the build
environment. When calling OutDir from Config instance, the out
was being sanitized again which is unnecessary.

Bug: b/118730755
Test: Ran unit test cases, "lunch" followed by "m" command.
Change-Id: Ieb4ffa1026c802c76c7369e8cdb3923a4c70f4b3

ui/build/config.go

@@ -638,7 +638,7 @@ func (c *configImpl) Arguments() []string {
 
 func (c *configImpl) OutDir() string {
 	if outDir, ok := c.environ.Get("OUT_DIR"); ok {
-		return filepath.Clean(outDir)
+		return outDir
 	}
 	return "out"
 }