BatteryService: implement test version of charge treshold script

Bin/set-battery-treshold.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env -S bash
+
+# Check if exectly one argument was provided
+if [ "$#" -ne 1 ]; then
+    echo "Error: Battery level not specified" >&2
+    echo "Usage: $0 <number>" >&2
+    exit 1
+fi
+
+# Check if argument is a number
+if ! [[ "$1" =~ ^[0-9]+$ ]]; then
+    echo "Error: Battery level must be a number" >&2
+    echo "Usage: $0 <number>" >&2
+    exit 1
+fi
+
+echo "$1" | pkexec tee ~/test