Simplify Crosstool Build Variables context

This cl merges two classes used to hold build variables context into one. Those
classes are (previously top-level) jcgd.build.lib.rules.cpp.Variables, and its
inner class View. Both represent a collection of build variables and imo it
makes sense to merge them to make the code simpler.

Also, I cleaned up the build variables api to use primitive strings or instances of VariableValueBuilders, and I've hidden subclasses of VariableValues.

Last but not least, I refactored the code to use immutable collections exclusively. That revealed that 'module_files' variable is sometimes registered twice. I want to clean this eventually ([]).

--
MOS_MIGRATED_REVID=139329823

0 files changed, 0 insertions, 0 deletions