Enhance upgrade_kernel_all task to work for 14.04(trusty) as well.

Recommended kernel version of contrail with Ubuntu Trusty is 3.13.0-35-generic,
However standard 14.04 LTS ISO comes with 3.13.0-24 kernel, so upgrading the kernel to
the recommended version before deploying contrail. Similar support required in server-manager
as well, so marking bug as partially fixed.

Change-Id: Ie194d6e6d64ba61d473644df5d89fcf9b0f1e283
Partail-Bug: 1390834
Merge "Enhance upgrade_kernel_all task to work for 14.04(trusty) as well."