rpc: use minimal mode by default

multinode-demo/bootstrap-validator.sh

@@ -129,6 +129,7 @@ args+=(
   --no-poh-speed-test
   --no-os-network-limits-test
   --no-wait-for-vote-to-start-leader
+  --full-rpc-api
 )
 default_arg --gossip-port 8001
 default_arg --log -

multinode-demo/validator.sh

@@ -248,6 +248,7 @@ default_arg --identity "$identity"
 default_arg --vote-account "$vote_account"
 default_arg --ledger "$ledger_dir"
 default_arg --log -
+default_arg --full-rpc-api
 
 if [[ $maybeRequireTower = true ]]; then
   default_arg --require-tower