[Autofill Assistant] Payment Request UI tweaks.

 - Update the status message with the PR prompt.
 - The progress bar should pulse when the PR is shown.

R=arbesser@google.com

Bug: 806868
Change-Id: I00e8ec07cc19c06bd13f49116955f0e09e422dd9
Reviewed-on: https://chromium-review.googlesource.com/c/1337494Reviewed-by: Stephane Zermatten <szermatt@chromium.org>
Commit-Queue: Mathias Carlen <mcarlen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608346}

chrome/android/java/src/org/chromium/chrome/browser/autofill_assistant/AutofillAssistantUiDelegate.java

@@ -787,6 +787,7 @@ class AutofillAssistantUiDelegate {
         // Make sure we wrap content in the container.
         mBottomBarAnimations.setBottomBarHeightToWrapContent();
         mPaymentRequest.show(mCarouselScroll, callback);
+        enableProgressBarPulsing();
     }
 
     /** Close and destroy the payment request UI. */
@@ -794,5 +795,6 @@ class AutofillAssistantUiDelegate {
         mPaymentRequest.close();
         mPaymentRequest = null;
         mBottomBarAnimations.setBottomBarHeightToFixed();
+        disableProgressBarPulsing();
     }
 }

components/autofill_assistant/browser/actions/get_payment_information_action.cc

@@ -57,6 +57,9 @@ void GetPaymentInformationAction::InternalProcessAction(
                      weak_ptr_factory_.GetWeakPtr(), delegate,
                      std::move(get_payment_information), std::move(callback)),
       get_payment_information.prompt(), supported_basic_card_networks);
+  if (get_payment_information.has_prompt()) {
+    delegate->ShowStatusMessage(get_payment_information.prompt());
+  }
 }
 
 void GetPaymentInformationAction::OnGetPaymentInformation(