[submodule] [202012] Update sonic-swss pointer (#8676)

* d240291 Update port_rates & rif_rates lua scripts to convert poll_interval to MS (#1855)
* a71a5d3 [acl mirror action] Mirror session ref count fix at acl rule attachment (#1761)
* 197f427 Fix vs test failure in test_buffer_traditional (#1881)
* 8471f42 Revert "[debugcounterorch] check if counter type is supported before querying… (#1789)" (#1884)

Signed-off-by: Volodymyr Samotiy <[email protected]>