Bump flatten-maven-plugin from 1.2.1 to 1.2.2 (#140)

Bumps [flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.2.1 to 1.2.2.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](mojohaus/flatten-maven-plugin@flatten-maven-plugin-1.2.1...flatten-maven-plugin-1.2.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

pom.xml

@@ -27,7 +27,7 @@
     <docker.image>${project.artifactId}</docker.image>
     <error-prone.version>2.3.4</error-prone.version>
     <extra-enforcer-rules.version>1.2</extra-enforcer-rules.version>
-    <flatten-maven-plugin.version>1.2.1</flatten-maven-plugin.version>
+    <flatten-maven-plugin.version>1.2.2</flatten-maven-plugin.version>
     <fmt-maven-plugin.version>2.9</fmt-maven-plugin.version>
     <guava.version>28.2-jre</guava.version>
     <jacoco-maven-plugin.version>0.8.5</jacoco-maven-plugin.version>