scripts: gconv_strip: convert to common --dry-run options

BUG=None
TEST=CQ passes

Change-Id: Ie8a30e19e9c2d81b4b8a70b6dcd340e1542419e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/4219578
Reviewed-by: Sergey Frolov <sfrolov@google.com>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/gconv_strip_unittest.py b/scripts/gconv_strip_unittest.py
index 71f3ca3..4b1831b 100644
--- a/scripts/gconv_strip_unittest.py
+++ b/scripts/gconv_strip_unittest.py
@@ -66,7 +66,7 @@
 
         self.PatchObject(gconv_strip.os, "lstat", return_value=_StubStat)
         self.PatchObject(gconv_strip.os, "unlink")
-        gmods.Rewrite(["charset_A", "charset_B"], dry_run=False)
+        gmods.Rewrite(["charset_A", "charset_B"], dryrun=False)
 
         expected = """
 #      from          to            module         cost