chore: fix The following signatures couldn't be verified because the …

…public key is not available: NO_PUBKEY 7FCC7D46ACCC4CF8

postgres-appliance/build_scripts/base.sh

@@ -253,6 +253,12 @@ if [ "$DEMO" != "true" ]; then
             echo "cd ${PGVERSION_BIN_PATH_TMP}"
             cd ${PGVERSION_BIN_PATH_TMP}
         else
+            wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
+
+            echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list
+
+            apt-get update
+
             apt-get install -y postgresql-$PGVERSION postgresql-client-$PGVERSION
             if [ -d ${PGVERSION_BIN_PATH} ]; then
                 echo "cd ${PGVERSION_BIN_PATH}"

postgres-appliance/build_scripts/prepare.sh

@@ -40,6 +40,8 @@ for t in deb deb-src; do
 done
 curl -s -o - https://www.postgresql.org/media/keys/ACCC4CF8.asc | gpg --dearmor > /etc/apt/trusted.gpg.d/apt.postgresql.org.gpg
 
+apt-get update
+
 # Clean up
 apt-get purge -y libcap2-bin
 apt-get autoremove -y