[db_migrator][201911] Support shared headroom in db_migrator on Mellanox platform#1261

Merged

liat-grozovik merged 11 commits intosonic-net:201911from

stephenxs:db_migrator-shared-headroom-201911

Jan 7, 2021

Commits on Nov 10, 2020

support to upgrade a switch from old version to one with shared headroom pool
stephenxs
committed

Commits on Nov 16, 2020

Address review comments
stephenxs
committed

Commits on Nov 20, 2020

Adjust 201811 buffer configuration according to info provided by MSFT
stephenxs
committed

Commits on Nov 23, 2020

Fix LGTM comments
stephenxs
committed

Commits on Dec 16, 2020

Address review comments
stephenxs
committed

Commits on Dec 17, 2020

Test whether the variable is None before referencing it
stephenxs
committed

Commits on Jan 4, 2021

Backport the infra for db_migrator unit test from master
stephenxs
committed

Commits on Jan 5, 2021