[maven-release-plugin] prepare for next development iteration

[maven-release-plugin] copy for tag java-sdk-2.10.0

[maven-release-plugin] copy for tag java-sdk-2.9.0

[maven-release-plugin] copy for tag java-sdk-2.8.0

[maven-release-plugin] copy for tag java-sdk-2.7.1

[maven-release-plugin] copy for tag java-sdk-2.7.0

[maven-release-plugin] copy for tag java-sdk-2.6.0

[maven-release-plugin] copy for tag java-sdk-2.5.0

[maven-release-plugin] copy for tag java-sdk-2.3.0

[maven-release-plugin] copy for tag java-sdk-2.1.0