Fix python proto srczip argument order

-P has to come before -D to have an effect on the files read from the
directory.

Fixes: 130160833
Test: atest acloud_test
Change-Id: I62a998f1ad1e3b45f590babbf39330955d368373
diff --git a/python/proto.go b/python/proto.go
index b3ffaa6..85ed1a5 100644
--- a/python/proto.go
+++ b/python/proto.go
@@ -35,12 +35,12 @@
 	// into a srcszip.
 	zipCmd := rule.Command().
 		Tool(ctx.Config().HostToolPath(ctx, "soong_zip")).
-		FlagWithOutput("-o ", srcsZipFile).
-		FlagWithArg("-C ", outDir.String()).
-		FlagWithArg("-D ", outDir.String())
+		FlagWithOutput("-o ", srcsZipFile)
 	if pkgPath != "" {
 		zipCmd.FlagWithArg("-P ", pkgPath)
 	}
+	zipCmd.FlagWithArg("-C ", outDir.String()).
+		FlagWithArg("-D ", outDir.String())
 
 	rule.Command().Text("rm -rf").Flag(outDir.String())