Starboard: support --v for verbosity

[yell0wd0g]

Starboard builds and in particular the nplb integration test support a command line flag
--min_log_level=(info|warning|error|fatal). Chromium binaries prefer in general --v
(or -v) for this purpose.

This CL adds logic to handle --v; to preserve previous behaviour, if and when both
--min_log_level and --v are present, the former takes precedence.

This CL also add unit tests for the translation between flag arguments and log level.
First instance of starboard_unittests !

Bug: 378879686
Bug: 384819454

[yell0wd0g]

@niranjanyardi can you PTAL at the starboard_unittest definition plz? Thanks!

[madhurajayaraman]

Looks good, but do we need to move anything around based on teh conversation in the Chrobalt 3P chat?

[niranjanyardi]

apart from the open comment lgtm

[yell0wd0g]

PTAL again!

[andrewsavage1]

As is, common_test won't run—it hasn't been added to the gha config code. If that's on purpose because other tests in the suite fail right now, okay, but if the test does currently pass let's run it.

I also think Niranjan is correct that the common_test target should be built with the starboard toolchain instead of the Cobalt toolchain, but that's something we can follow up with

[yell0wd0g]

As is, common_test won't run—it hasn't been added to the gha config code. If that's on purpose because other tests in the suite fail right now, okay, but if the test does currently pass let's run it.

I also think Niranjan is correct that the common_test target should be built with the starboard toolchain instead of the Cobalt toolchain, but that's something we can follow up with

I say let's land this CL/PR, which is about the logging --v, and work on fixing+folding all unittests into starboard_unittests in subsequent CLs, let me make a bug for it.