PR InfiniTimeOrg#857: InfiniPaint: add missing include algorithm for …

…std::fill

Squashed commit of the following:

commit ca36d29
Author: Reinhold Gschweicher <pyro4hell@gmail.com>
Date:   Wed Oct 13 23:35:54 2021 +0200

    InfiniPaint: add missing include algorithm for std::fill

src/displayapp/screens/InfiniPaint.cpp

@@ -2,6 +2,8 @@
 #include "displayapp/DisplayApp.h"
 #include "displayapp/LittleVgl.h"
 
+#include <algorithm> // std::fill
+
 using namespace Pinetime::Applications::Screens;
 
 InfiniPaint::InfiniPaint(Pinetime::Applications::DisplayApp* app,