Only enable the Keyboard device in the XcbKeyboard unit tests (#4682)

This prevents other input devices from interfering with the expected calls
that the Keyboard tests should make.

Signed-off-by: Chris Burel <burelc@amazon.com>

Code/Framework/AzFramework/Platform/Common/Xcb/AzFramework/XcbNativeWindow.cpp

@@ -10,6 +10,7 @@
 #include <AzFramework/Windowing/NativeWindow.h>
 #include <AzFramework/XcbNativeWindow.h>
 #include <AzFramework/XcbConnectionManager.h>
+#include <AzFramework/XcbInterface.h>
 
 #include <xcb/xcb.h>