Changing boot logo in 4.x and 5.x player versions

Player versions 4.x and beyond are based on newer OS versions of Raspberry and do not support bootup videos. Instead you can add a png image to show up during boot. Instructions to do the same are as follows.

1. Create a boot-logo playlist with the boot-logo.png and deploy it to the group as the last scheduled playlist (additional playlist) so that the logo is copied to the player.
2. Execute the following command

sudo cp /home/pi/media/boot-logo.png /usr/share/plymouth/themes/pix/splash.png
sudo plymouth-set-default-theme --rebuild-initrd pix &
sudo cp  /home/pi/media/boot-logo.png /home/pi/player2/public/img/pisignage-logo.png