Update Fault rules to use status codes

Author: JackPlowman

proxies/live/apiproxy/policies/RaiseFault.400BadRequest.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<!--
+ This policy raises a 400 error response for an application failure.
+
+ Raisefault policies stop the execution of the current flow and move to the error flow, which returns the error response defined here to the requesting application.
+
+ For more information on RaiseFault policies within Apigee see the following resource:
+    * https://docs.apigee.com/api-platform/reference/policies/raise-fault-policy
+-->
+<RaiseFault async="false" continueOnError="false" enabled="true" name="RaiseFault.400BadRequest">
+    <DisplayName>RaiseFault.400BadRequest</DisplayName>
+    <Properties/>
+    <FaultResponse>
+        <Set>
+            <Headers>
+              <Header name="Content-Type">application/fhir+json</Header>
+            </Headers>
+            <StatusCode>400</StatusCode>
+            <ReasonPhrase>BadRequest</ReasonPhrase>
+        </Set>
+    </FaultResponse>
+    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
+</RaiseFault>

proxies/live/apiproxy/targets/target.xml

@@ -27,23 +27,29 @@
         </Response>
     </PostFlow>
     <FaultRules>
-        <FaultRule name="404_Not_Found">
+        <FaultRule name="400_Bad_Request">
             <Step>
-                <Name>RaiseFault.404NotFound</Name>
+                <Name>RaiseFault.400BadRequest</Name>
             </Step>
-            <Condition>response.header.x-amzn-ErrorType = "IncompleteSignatureException"</Condition>
+            <Condition>response.status.code = 400</Condition>
         </FaultRule>
-        <FaultRule name="unauthorized">
+        <FaultRule name="Unauthorized">
             <Step>
                 <Name>RaiseFault.401Unauthorized</Name>
             </Step>
             <Condition>oauthV2.OauthV2.VerifyAccessToken.failed = true or fault.name = "invalid_access_token" or fault.name = "InvalidAccessToken" or fault.name = "access_token_not_approved" or fault.name = "apiresource_doesnot_exist" or fault.name = "InvalidAPICallAsNo" or fault.name = "ApiProductMatchFound" or fault.name = "access_token_expired"</Condition>
         </FaultRule>
-        <FaultRule name="internal_server_error">
+        <FaultRule name="404_Not_Found">
+            <Step>
+                <Name>RaiseFault.404NotFound</Name>
+            </Step>
+            <Condition>response.header.x-amzn-ErrorType = "IncompleteSignatureException"</Condition>
+        </FaultRule>
+        <FaultRule name="500_Internal_Server_Error">
             <Step>
                 <Name>RaiseFault.500InternalServerError</Name>
             </Step>
-            <Condition>response.status_code = "400"</Condition>
+            <Condition>response.status.code = 500</Condition>
         </FaultRule>
     </FaultRules>
     <HTTPTargetConnection>