Dependency Convergence error for Kotlin library

## Describe the proposal
I propose to add the [Maven Enforcer Plugin](https://maven.apache.org/enforcer/maven-enforcer-plugin/) to the project build, and more specifically, to enforce the ["Dependency Convergence" rule](https://maven.apache.org/enforcer/enforcer-rules/dependencyConvergence.html).
This rule ensures that for each dependency, it is possible to resolve to one and only one version.
Quoting an example from the documentation:

> This rule requires that dependency version numbers converge. If a project has two dependencies, A and B, both depending on the same artifact, C, this rule will fail the build if A depends on a different version of C than the version of C depended on by B.

Currently, dependency version numbers do not converge. I have attached a [sample project](https://github.com/dapr/java-sdk/files/6572018/dapr-dependency-convergence.zip) which depends only on Dapr, that illustrates this. If you run `mvn validate` on the project, you see:

```
Dependency convergence error for org.jetbrains.kotlin:kotlin-stdlib:1.4.0 paths to dependency are:
+-it.mulders.dapr:dapr-dependency-convergence:1.0-SNAPSHOT
+-io.dapr:dapr-sdk:1.1.0
+-com.squareup.okhttp3:okhttp:4.9.0
+-com.squareup.okio:okio:2.8.0
+-org.jetbrains.kotlin:kotlin-stdlib:1.4.0
and
+-it.mulders.dapr:dapr-dependency-convergence:1.0-SNAPSHOT
+-io.dapr:dapr-sdk:1.1.0
+-com.squareup.okhttp3:okhttp:4.9.0
+-org.jetbrains.kotlin:kotlin-stdlib:1.4.10
```

So, my proposal is two-fold:
1. Add the plugin + rule to prevent this kind of situation in the future
2. Solve the current convergence error

PS. I'm not sure if this should be a proposal or rather a bug report. Feel free to change to bug report if you think that's more appropriate.