Upgrade com.google.protobuf version from 3.21.3 to 4.26.1 in java subproject

[almaspite98]

• I have searched the issues of this repository and believe that this is not a duplicate.

Summary

In our project we are using chirpstack-api as an external dependency, but we cannot upgrade the com.google.protobuf package, because chirpstack-api is transitively forces an older version containing now deprecated calls in the generated sources.

Implementation description

• Update the protobuf version to latest stable version in chirpstack-api/java/pom.xml
• Test and fix any compilation issues from the source generation

Can you implement this by yourself and make a pull request?

Not at the moment.