Update worker exception

[jja725]

What changes are proposed in this pull request?

Replace checked exception with run time exception in worker when appropriate.

Why are the changes needed?

code quality

Does this PR introduce any user facing changes?

na

[alluxio-bot]

Automated checks report:

• Commits associated with Github account: PASS
• PR title follows the conventions: FAIL
  • The title of the PR does not pass all the checks. Please fix the following issues:
    • First word of title ("Harden") is not an imperative verb. Please use one of the valid words

Some checks failed. Please fix the reported issues and reply 'alluxio-bot, check this please' to re-run checks.

[alluxio-bot]

Automated checks report:

• Commits associated with Github account: PASS
• PR title follows the conventions: PASS

All checks passed!

[rongrong]

alluxio-bot, merge this please