BUG: compile Java example, fix Java Gaussian Example

The list accumulate variable was only local scope, and so there were
no Java example being built. By setting to the parent scope the list
of java file to compile is accumulated.

Change-Id: Ie1e5ea8f8d361dd63c2dbc605cd591988156f3cd
Merge topic 'SIMPLEITK-410_UseOptionBUILD_EXAMPLES' into next

c730a195 BUG: compile Java example, fix Java Gaussian Example