Refactor to use SpEL in function properties

* Clean up per review

applications/processor/http-request-processor/README.adoc

@@ -43,17 +43,13 @@ The **$$http-request$$** $$processor$$ has the following options:
 == Options
 
 //tag::configuration-properties[]
-$$http.request.processor.body$$:: $$The (static) request body; if neither this nor bodyExpression is provided, the payload will be used.$$ *($$Object$$, default: `$$<none>$$`)*
-$$http.request.processor.body-expression$$:: $$A SpEL expression to derive the request body from the incoming message.$$ *($$Expression$$, default: `$$<none>$$`)*
-$$http.request.processor.expected-response-type$$:: $$The type used to interpret the response.$$ *($$Class<?>$$, default: `$$<none>$$`)*
-$$http.request.processor.headers$$:: $$A Map of HTTP request headers.$$ *($$HttpHeaders$$, default: `$$<none>$$`)*
-$$http.request.processor.headers-expression$$:: $$A SpEL expression used to derive the http headers map to use.$$ *($$Expression$$, default: `$$<none>$$`)*
-$$http.request.processor.http-method$$:: $$The kind of http method to use.$$ *($$HttpMethod$$, default: `$$<none>$$`, possible values: `GET`,`HEAD`,`POST`,`PUT`,`PATCH`,`DELETE`,`OPTIONS`,`TRACE`)*
-$$http.request.processor.http-method-expression$$:: $$A SpEL expression to derive the request method from the incoming message.$$ *($$Expression$$, default: `$$<none>$$`)*
-$$http.request.processor.reply-expression$$:: $$A SpEL expression used to compute the final result, applied against the whole http {@link org.springframework.http.ResponseEntity}.$$ *($$Expression$$, default: `$$body$$`)*
-$$http.request.processor.timeout$$:: $$Request timeout in milliseconds.$$ *($$Long$$, default: `$$30000$$`)*
-$$http.request.processor.url$$:: $$The URL to issue an http request to, as a static value.$$ *($$String$$, default: `$$<none>$$`)*
-$$http.request.processor.url-expression$$:: $$A SpEL expression against incoming message to determine the URL to use.$$ *($$Expression$$, default: `$$<none>$$`)*
+$$http.request.body-expression$$:: $$A SpEL expression to derive the request body from the incoming message.$$ *($$Expression$$, default: `$$<none>$$`)*
+$$http.request.expected-response-type$$:: $$The type used to interpret the response.$$ *($$Class<?>$$, default: `$$<none>$$`)*
+$$http.request.headers-expression$$:: $$A SpEL expression used to derive the http headers map to use.$$ *($$Expression$$, default: `$$<none>$$`)*
+$$http.request.http-method-expression$$:: $$A SpEL expression to derive the request method from the incoming message.$$ *($$Expression$$, default: `$$'GET'$$`)*
+$$http.request.reply-expression$$:: $$A SpEL expression used to compute the final result, applied against the whole http {@link org.springframework.http.ResponseEntity}.$$ *($$Expression$$, default: `$$body$$`)*
+$$http.request.timeout$$:: $$Request timeout in milliseconds.$$ *($$Long$$, default: `$$30000$$`)*
+$$http.request.url-expression$$:: $$A SpEL expression against incoming message to determine the URL to use.$$ *($$Expression$$, default: `$$<none>$$`)*
 //end::configuration-properties[]
 
 //end::ref-doc[]