SAMZA-2441: Update ApplicationRunnerMain#ApplicationRunnerCommandLine not to load local file

[kw2542]

This is backward incompatible and is only supposed to be included in Samza 1.5

Design:
https://cwiki.apache.org/confluence/display/SAMZA/SEP-23%3A+Simplify+Job+Runner

Changes:

1. Override ApplicationRunnerCommandLine#loadConfig not to invoke config loader as ApplicationRunners handles initial config and full job config themselves.
2. Add JobRunnerCommandLine to load full job config for JobRunner to keep consistent with previous behavior as it still needs full job config for special use cases.

API Changes:
None

Upgrade Instructions:
None

Usage Instructions:
None

Tests:

1. Unit Tests

[cameronlee314]

Do you feel that the "base" use case for CommandLine is to need the full config? To me, it looks a little awkward to need to override loadConfig here with an implementation which is almost the same as the base loadConfig.
I suppose one alternative would be to make this impl here the base impl, and then have each use case call ConfigUtil.loadConfig if is needs it. What do you see as the tradeoffs?

[kw2542]

Good question, in all 13 direct usage of CommandLine, and 5 sub classes of CommandLine, they are all expecting full job configs to work properly, e.g. RocksDbReadingTool extends CommandLine to read full job config before being able to read data from Rocks DB, which is being invoked by CLI.

If we change CommandLine to the other way, that means we need to invoke ConfigUtil.loadConfig explicitly in 13 places, and override loadConfigs in 5 sub classes to invoke ConfigUtil.loadConfig too, compared to overriding once in ApplicationRunnerCommandLine only.

I would prefer the current way to keep the base class to serve majority use case.

[lhaiesp]

LGTM