Implement "premium price ack required" checkbox

Implement a checkbox in the "Resources" tab to allow registrars to toggle
their "premium price ack required" flag.

Tested:
  Verfied the console functionality by hand.  I've started work on an
  automated test, but we can't actually test those from blaze and the
  kokoro tests are way too time-consuming to be practical for development, so
  we're going to have to either find a way to run those locally outside of
  the normal process or make do without a test.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=190212177

java/google/registry/ui/server/registrar/RegistrarPaymentAction.java

@@ -157,7 +157,7 @@ public final class RegistrarPaymentAction implements Runnable, JsonAction {
 
   @Override
   public Map<String, Object> handleJsonRequest(Map<String, ?> json) {
-    Registrar registrar = sessionUtils.getRegistrarForAuthResult(request, authResult);
+    Registrar registrar = sessionUtils.getRegistrarForAuthResult(request, authResult, false);
     logger.infofmt("Processing payment: %s", json);
     String paymentMethodNonce;
     Money amount;