Add missing key for bionic-security repository

The devstack install on ubuntu jammy (22.04) fails to check the
signature for the bionic-security repo and exits, as seen in
https://github.com/gophercloud/gophercloud/issues/2701.

This commit adds the required key.

Change-Id: Ifab19c36fbca1813dae35d65750deed4fd81b91c

devstack/plugin.sh

@@ -193,6 +193,7 @@ function configure_mongodb {
             wget -qO - https://www.mongodb.org/static/pgp/server-6.0.asc | sudo apt-key add -
             echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu jammy/mongodb-org/6.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-6.0.list
             echo "deb http://security.ubuntu.com/ubuntu bionic-security main" | sudo tee /etc/apt/sources.list.d/bionic-security.list
+            sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32
             sudo apt update
             install_package libssl1.1
             install_package mongodb-org

tools/test-setup.sh

@@ -38,6 +38,7 @@ if [[ $ubuntu_version == '22.04' ]]; then
     wget -qO - https://www.mongodb.org/static/pgp/server-6.0.asc | sudo apt-key add -
     echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu jammy/mongodb-org/6.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-6.0.list
     echo "deb http://security.ubuntu.com/ubuntu bionic-security main" | sudo tee /etc/apt/sources.list.d/bionic-security.list
+    sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32
     sudo apt update
     sudo apt install -y libssl1.1
     sudo apt install -y mongodb-org