Update Dockerfiles (#1422)

This commit
- updates the Azul JDK version on CentOS 7. This is a temporary workaround that will not work on aarch64
- removes Ubuntu 21.04 and 21.10 since they're EOL and are not used on CI (judging by the downstream pipeline)
- adds support for Ubuntu 22.04
diff --git a/buildkite/bazelci.py b/buildkite/bazelci.py
index e920732..fbeddd1 100755
--- a/buildkite/bazelci.py
+++ b/buildkite/bazelci.py
@@ -550,20 +550,12 @@
         "docker-image": f"gcr.io/{DOCKER_REGISTRY_PREFIX}/ubuntu2004-java11-kythe",
         "python": "python3.8",
     },
-    "ubuntu2104": {
-        "name": "Ubuntu 21.04 (OpenJDK 11, gcc 10.3.0)",
-        "emoji-name": ":ubuntu: 21.04 (OpenJDK 11, gcc 10.3.0)",
+    "ubuntu2204": {
+        "name": "Ubuntu 22.04 (OpenJDK 17, gcc 11.2.0)",
+        "emoji-name": ":ubuntu: 22.04 (OpenJDK 17, gcc 11.2.0)",
         "downstream-root": "/var/lib/buildkite-agent/builds/${BUILDKITE_AGENT_NAME}/${BUILDKITE_ORGANIZATION_SLUG}-downstream-projects",
         "publish_binary": [],
-        "docker-image": f"gcr.io/{DOCKER_REGISTRY_PREFIX}/ubuntu2104-java11",
-        "python": "python3",
-    },
-    "ubuntu2110": {
-        "name": "Ubuntu 21.10 (OpenJDK 17, gcc 11.2.0)",
-        "emoji-name": ":ubuntu: 21.10 (OpenJDK 11, gcc 11.2.0)",
-        "downstream-root": "/var/lib/buildkite-agent/builds/${BUILDKITE_AGENT_NAME}/${BUILDKITE_ORGANIZATION_SLUG}-downstream-projects",
-        "publish_binary": [],
-        "docker-image": f"gcr.io/{DOCKER_REGISTRY_PREFIX}/ubuntu2110-java17",
+        "docker-image": f"gcr.io/{DOCKER_REGISTRY_PREFIX}/ubuntu2204-java17",
         "python": "python3",
     },
     "macos": {