[Password Manager] Restrict IsTheHotNewBubbleUIEnabled to Aura and Mac

ChromePasswordManagerClient::IsTheHotNewBubbleUIEnabled needs to return false on Android, because there is no bubble for Android.

Unintentionally, I (vabr) misinformed dconnelly in https://codereview.chromium.org/444603003/diff/20001/chrome/browser/password_manager/chrome_password_manager_client.cc#newcode357 that IsTheHotNewBubbleUIEnabled is not compiled on Android at all, whereas the truth is, it is only not compiled for Androd WebView.
As a consequence, IsTheHotNewBubbleUIEnabled started to return possibly true on Android after https://codereview.chromium.org/505123002 landed, causing a crash on the bots.

BUG=328847,409622

Review URL: https://codereview.chromium.org/529743002

Cr-Commit-Position: refs/heads/master@{#292884}

chrome/browser/password_manager/chrome_password_manager_client.cc

@@ -485,6 +485,9 @@ bool ChromePasswordManagerClient::IsURLPasswordWebsiteReauth(
 }
 
 bool ChromePasswordManagerClient::IsTheHotNewBubbleUIEnabled() {
+#if !defined(USE_AURA) && !defined(OS_MACOSX)
+  return false;
+#endif
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kDisableSavePasswordBubble))
     return false;