Bump Braintree hosted scripts version to 3.52.0

The 3.52.0 version is the minimum version required to be able to
introduce the 3D Secure 2 support.

app/views/spree/shared/_paypal_braintree_head_scripts.html.erb

@@ -1,18 +1,18 @@
 <% content_for :head do %>
-  <script src="https://js.braintreegateway.com/web/3.34.0/js/client.min.js"></script>
-  <script src="https://js.braintreegateway.com/web/3.34.0/js/data-collector.min.js"></script>
+  <script src="https://js.braintreegateway.com/web/3.52.0/js/client.min.js"></script>
+  <script src="https://js.braintreegateway.com/web/3.52.0/js/data-collector.min.js"></script>
 
   <% if current_store.braintree_configuration.paypal? %>
-    <script src="https://js.braintreegateway.com/web/3.34.0/js/paypal-checkout.min.js"></script>
+    <script src="https://js.braintreegateway.com/web/3.52.0/js/paypal-checkout.min.js"></script>
     <script src="https://www.paypalobjects.com/api/checkout.js" data-version-4></script>
   <% end %>
 
   <% if current_store.braintree_configuration.credit_card? %>
-    <script src="https://js.braintreegateway.com/web/3.34.0/js/hosted-fields.min.js"></script>
+    <script src="https://js.braintreegateway.com/web/3.52.0/js/hosted-fields.min.js"></script>
   <% end %>
 
   <% if current_store.braintree_configuration.apple_pay? %>
-    <script src="https://js.braintreegateway.com/web/3.34.0/js/apple-pay.min.js"></script>
+    <script src="https://js.braintreegateway.com/web/3.52.0/js/apple-pay.min.js"></script>
   <% end %>
 
   <%= javascript_include_tag "solidus_paypal_braintree/checkout" %>