Simplify "make iso" process

Resolving all the dependencies is cumbersome and time consuming,
and missing one minor step can result in a dev environment that
can not build an ISO (but does not necessarily tell you what is missing).

Proposed script helps to ensure that all the dependencies are installed.

Change-Id: Ib71c8790e3cb2902d91e06b7ea7cc92657c52385
Related-Bug: #1324723
Merge "Simplify "make iso" process"