PSM: Always enable PSM switch by default

Enable PSM protocol by default during the initial enrollment.

BUG=chromium:1130590

Change-Id: Iab0adabc30e5e47eb8bde814751f135627161f75
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2552382Reviewed-by: Roland Bock <rbock@google.com>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Pavol Marko <pmarko@chromium.org>
Commit-Queue: Amr Aboelkher <amraboelkher@google.com>
Cr-Commit-Position: refs/heads/master@{#830222}

chrome/browser/chromeos/login/enrollment/auto_enrollment_controller.cc

@@ -391,7 +391,7 @@ bool AutoEnrollmentController::IsPrivateSetMembershipEnabled() {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
 
   if (!command_line->HasSwitch(switches::kEnterpriseEnablePrivateSetMembership))
-    return false;  // Disabled by default.
+    return true;  // Enabled by default.
 
   std::string command_line_mode = command_line->GetSwitchValueASCII(
       switches::kEnterpriseEnablePrivateSetMembership);