[maven-release-plugin] prepare release gitkitclient-1.2.3
[maven-release-plugin] prepare release gitkitclient-1.2.3

r351574nc3/identity-toolkit-java-client,liujin-google/identity-toolkit-java-client,google/identity-toolkit-java-client,fengshao0907/identity-toolkit-java-client,skinzer/identity-toolkit-java-client