Remove account check for assistant optin first run ui

Bug: b/112564431
Test: Manual Test
Change-Id: I6750c3d4c8727948165bf821b417cb47d5db0427
Reviewed-on: https://chromium-review.googlesource.com/1185862Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Yue Li <updowndota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585285}

chrome/browser/chromeos/first_run/first_run.cc

@@ -137,7 +137,7 @@ class DialogLauncher : public content::NotificationObserver {
 
 #if BUILDFLAG(ENABLE_CROS_LIBASSISTANT)
     // Launch Assistant OOBE flow if Assistant is enabled.
-    if (account_supported && chromeos::switches::IsAssistantEnabled()) {
+    if (chromeos::switches::IsAssistantEnabled()) {
       chromeos::AssistantOptInDialog::Show();
       delete this;
       return;