[submodule] [202012] Update sonic-swss pointer

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

Signed-off-by: Volodymyr Samotiy <volodymyrs@nvidia.com>