The script
'size=$(adb shell dumpsys window | grep -Eo 'init=\d+x\d+' | head -1 | cut -d= -f 2)'
can not find the string 'init=480x854'

Should change to
'size=$(adb shell dumpsys window | grep -Eo 'init=[0-9]+x[0-9]+' | head -1 | cut -d= -f 2)'