Re-add RBE platform to gerrit pipeline

Closes bazelbuild#1820.

To correctly activate RBE platfor--remote_executor option must be
specified in gerrit.yml:

  --remote_executor=grpcs://remotebuildexecution.googleapis.com

pipelines/gerrit.yml

@@ -22,3 +22,17 @@ platforms:
       - "--test_tag_filters=-git,-git-protocol-v2,-git-upload-archive,-ssh"
     test_targets:
       - "//..."
+  rbe_ubuntu2204:
+    build_flags:
+      - "--remote_executor=grpcs://remotebuildexecution.googleapis.com"
+    build_targets:
+      - "//:release"
+      - "//:api-skip-javadoc"
+    test_flags:
+      - "--config=remote"
+      - "--remote_executor=grpcs://remotebuildexecution.googleapis.com"
+      - "--experimental_remote_cache_async"
+      - "--experimental_remote_merkle_tree_cache"
+      - "--remote_download_minimal"
+    test_targets:
+      - "//..."