Use let instead of const

Author: CrisBarreiro

app/src/main/res/raw/webviewcompat_test_script.js

@@ -1,10 +1,10 @@
 let supportedMessages = ["ContextMenuOpened", "PageStarted"];
 
-const delay = $DELAY$;
-const postInitialPing = $POST_INITIAL_PING$;
-const replyToNativeMessages = $REPLY_TO_NATIVE_MESSAGES$;
+let delay = $DELAY$;
+let postInitialPing = $POST_INITIAL_PING$;
+let replyToNativeMessages = $REPLY_TO_NATIVE_MESSAGES$;
 
-  const pingMessage = 'Ping:' + window.location.href + ' ' + delay + 'ms'
+let pingMessage = 'Ping:' + window.location.href + ' ' + delay + 'ms'
 
 
 if (postInitialPing) {