Update plugins compatibility matrix for Gerrit v3.2

Change-Id: Ia44899e34e15ae0a7d03b0c26ba21947e16d8840
diff --git a/tools/plugins.py b/tools/plugins.py
index e041b67..f943411 100644
--- a/tools/plugins.py
+++ b/tools/plugins.py
@@ -16,7 +16,7 @@
 from tqdm import tqdm
 
 
-BRANCHES = ["master"] + [f"stable-{version}" for version in ["3.1", "3.0", "2.16"]]
+BRANCHES = ["master"] + [f"stable-{version}" for version in ["3.2", "3.1", "3.0", "2.16"]]
 CI = "https://gerrit-ci.gerritforge.com"
 GERRIT = "https://gerrit-review.googlesource.com"
 GITILES = "https://gerrit.googlesource.com"