Bump error_prone_core from 2.3.4 to 2.4.0
Bump error_prone_core from 2.3.4 to 2.4.0

Bumps [error_prone_core](https://github.com/google/error-prone) from 2.3.4 to 2.4.0.
- [Release notes](https://github.com/google/error-prone/releases)
- [Commits](https://github.com/google/error-prone/compare/v2.3.4...v2.4.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
kruton/connectbot,connectbot/connectbot,kruton/connectbot,iiordanov/BSSH,iiordanov/BSSH,kruton/connectbot,connectbot/connectbot,iiordanov/BSSH,connectbot/connectbot