Use std::map.contains as per latest c++

This commit replaces occurrences of 'find' with
'contains' to access elements in a std::map
according to the latest C++ standard (since C++20).

However, contains() is not suitable in all situations
as in the case where we want to use the element contained
in the map using contains(), then it would do 2 searches
instead of 1 in the case where we use find() which fetches
the element from the map also.

Here are some relevant links to C++ documentation and
resources:

[1]: https://en.cppreference.com/w/cpp/container/map/find
[2]: https://en.cppreference.com/w/cpp/container/map/contains
[3]: https://wg21.link/N4861

Signed-off-by: Sagar Srinivas <sagar.srinivas@ibm.com>
Change-Id: If589e52026417c1c14a6a946e48826b749034e9a
diff --git a/libpldmresponder/event_parser.cpp b/libpldmresponder/event_parser.cpp
index 303a553..23ffa2c 100644
--- a/libpldmresponder/event_parser.cpp
+++ b/libpldmresponder/event_parser.cpp
@@ -69,8 +69,7 @@
             dbusInfo.propertyType = dbus.value("property_type", "");
             if (dbusInfo.objectPath.empty() || dbusInfo.interface.empty() ||
                 dbusInfo.propertyName.empty() ||
-                (supportedDbusPropertyTypes.find(dbusInfo.propertyType) ==
-                 supportedDbusPropertyTypes.end()))
+                !supportedDbusPropertyTypes.contains(dbusInfo.propertyType))
             {
                 error(
                     "Invalid dbus config, OBJPATH= {DBUS_OBJ_PATH} INTERFACE={DBUS_INTF} PROPERTY_NAME={DBUS_PROP} PROPERTY_TYPE={DBUS_PROP_TYPE}",