refactor: convert contentScriptsUtils to Typescript

Change-Id: I78031a291a34198ac6335a4ee42eb23753f2c37b
diff --git a/src/contentScripts/publicThread.js b/src/contentScripts/publicThread.js
index bc12236..b5864cd 100644
--- a/src/contentScripts/publicThread.js
+++ b/src/contentScripts/publicThread.js
@@ -1,4 +1,4 @@
-import {injectStylesheet} from '../common/contentScriptsUtils.js';
+import {injectStylesheet} from '../common/contentScriptsUtils';
 import {getOptions} from '../common/options/optionsUtils.js';
 import {redirectIfApplicable} from '../redirect/index.js';