Add the 'login' command to gtech_tool

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=225394580

java/google/registry/tools/GtechTool.java

@@ -60,6 +60,8 @@ public final class GtechTool {
       "list_registrars",
       "list_tlds",
       "lock_domain",
+      "login",
+      "logout",
       "registrar_contact",
       "setup_ote",
       "uniform_rapid_suspension",