[Portable BQ] default null list to empty list

[ahmedabu98]

Fixes a problem where, in the DLQ, failed rows containing null values for list fields will fail to convert to Beam Rows.

[ahmedabu98]

assign set of reviewers

[github-actions]

Assigning reviewers. If you would like to opt out of this review, comment assign to next reviewer:

R: @m-trieu for label java.
R: @shunping for label io.

Available commands:

• stop reviewer notifications - opt out of the automated review tooling
• remind me after tests pass - tag the comment author after tests pass
• waiting on author - shift the attention set back to the author (any comment or push by the author will return the attention set to the reviewers)

The PR bot will only process comments in the main thread (not review comments).

[liferoad]

Can we cherry-pick this one? @jrmccluskey

[jrmccluskey]

@liferoad RC1 is already out for a vote, so to get this in 2.63.0 we'd need to either find a regression that needs fixing in that RC or deem this fix important enough to move to an RC2 anyway

[ahmedabu98]

I don't think it warrants a new RC since this isn't a new regression introduced in 2.63.0.

If there happens to be a new RC for a different reason, it'd be cool to include this, but up to @jrmccluskey's judgement

[jrmccluskey]

I already have another PR cherry picked to the release branch in case we go to RC2, so feel free to open a cherry pick PR once this is merged

[jrmccluskey]

Looks like we're heading to RC2 if you want to get this in @ahmedabu98

[ahmedabu98]

Thanks for the heads up.
sorry, had to re-run the java precommit quite a bit because of flakes