Use bazelisk for releasing Gerrit

Change-Id: I3bd119765ef231ce98f38f0357aba09322a3e094
diff --git a/jenkins-docker/slave-release/gerrit-release.sh b/jenkins-docker/slave-release/gerrit-release.sh
index 191a8dd..ffe1922 100755
--- a/jenkins-docker/slave-release/gerrit-release.sh
+++ b/jenkins-docker/slave-release/gerrit-release.sh
@@ -42,7 +42,7 @@
 git tag -f -s -m "v$version" "v$version"
 git submodule foreach git tag -f -s -m "v$version" "v$version"
 
-bazel build release Documentation:searchfree
+bazelisk build release Documentation:searchfree
 ./tools/maven/api.sh install
 
 echo -n "Checking Gerrit version ... "