examples: add mdev example for Android phone

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

examples/mdev.conf.change_blockdev.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# Seconds to try to reread partition table
+cnt=60
+
+exec </dev/null
+exec >"/tmp/${0##*/}.$$.out"
+exec 2>&1
+
+(
+echo "Running: $0"
+echo "Env:"
+env | sort
+
+while sleep 1; test $cnt != 0; do
+	echo "Trying to rereat partition table on $DEVNAME ($cnt)"
+	: $((cnt--))
+	test -e "$DEVNAME" || { echo "$DEVNAME doesn't exist, aborting"; exit 1; }
+	#echo "$DEVNAME exists"
+	blockdev --rereadpt "$DEVNAME" && break
+	echo "blockdev --rereadpt failed, exit code: $?"
+done
+echo "blockdev --rereadpt succeeded"
+) &