init: Add support for logrotate_max_size cmdline args

This patch adds support for setting logrotate_max_size in cmdline args:
logrotate_max_size=number
This informations are sued to set logrotate_max_size during
an auto-installation.

Change-Id: Ide628895f15ed8f8dc5c047228300868a53f2a0c
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=986830
Signed-off-by: hadong <hadong0720@gmail.com>