fix(coap-core): add mapping for 204 http status to C205_CONTENT code

Author: szysas

coap-core/src/main/java/com/mbed/coap/packet/Code.java

@@ -130,6 +130,9 @@ public static Code fromHttp(int httpStatus, Method method) {
                 if (method == Method.DELETE) {
                     return C202_DELETED;
                 }
+                if (method == Method.GET || method == Method.FETCH) {
+                    return C205_CONTENT;
+                }
                 return C204_CHANGED;
 
 

coap-core/src/test/java/com/mbed/coap/packet/CodeTest.java

@@ -112,6 +112,7 @@ public void shouldConvertHttpToCoapCode() {
         assertEquals(Code.C201_CREATED, fromHttp(202, POST));
         assertEquals(Code.C202_DELETED, fromHttp(202, DELETE));
         assertEquals(Code.C202_DELETED, fromHttp(204, DELETE));
+        assertEquals(Code.C205_CONTENT, fromHttp(204, GET));
 
         assertEquals(Code.C203_VALID, fromHttp(304, GET));