[Security] Bump protobufjs from 5.0.2 to 5.0.3
[Security] Bump protobufjs from 5.0.2 to 5.0.3

Bumps [protobufjs](https://github.com/dcodeIO/protobuf.js) from 5.0.2 to 5.0.3. **This update includes security fixes.**
- [Release notes](https://github.com/dcodeIO/protobuf.js/releases)
- [Changelog](https://github.com/dcodeIO/protobuf.js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/dcodeIO/protobuf.js/compare/5.0.2...5.0.3)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
dyaa/loopback-connector-firestore,dyaa/loopback-connector-firestore