Dynamic threshold setting changed to 0 and WRED profile green min threshold set to 250000 for Tomahawk devices

Changed the dynamic threshold settings in pg_profile_lookup.ini
Added a macro for WRED profiles in qos.json.j2 for Tomahawk devices
Necessary changes made in qos.config.j2 to use the macro if present

Signed-off-by: Neetha John <nejo@microsoft.com>

Signed-off-by: SuvarnaMeenakshi <sumeenak@microsoft.com>

Signed-off-by: Akhilesh Samineni <akhilesh.samineni@broadcom.com>

…f first boot into new image (#4538)

1. ebtables -t filter -A FORWARD -p 802_1Q --vlan-encap 0806 -j DROP
The ARP packet with vlan tag can't match the default rule.

Signed-off-by: wangshengjun <wangshengjun@asterfusion.com>

[Vnet] Fix NameError for 'swsssdk' and align output (#902)
[config] Add 'interface transceiver' subgroup with 'lpmode' and 'reset' subcommands (#904)
Improved route_check tool and adopt to 20191130 image. (#898)

#4477)

* Multi DB with namespace support, Introducing the database_global.json file
for supporting accessing DB's in other namespaces for service running in
linux host

* Updates based on comments

* Adding the j2 templates for database_config and database_global files.

* Updating to retrieve the redis DIR's to be mounted from database_global.json file.

* Additional check to see if asic.conf file exists before sourcing it.

* Updates based on PR comments discussion.

* Review comments update

* Updates to the argument "-n" for namespace used in both context of parsing minigraph and multi DB access.

* Update with the attribute "persistence_for_warm_boot" that was added to database_config.json file earlier.

* Removing the database_config.json file to avioid confusion in future.
We use the database_config.json.j2 file to generate database_config.json files dynamically.

* Update the comments for sudo usage in docker_image_ctrl.j2

* Update with the new logic in PING PONG tests using sonic-db-cli. With this we wait till the
PONG response is received when redis server is up.

* Similar changes in swss and syncd scripts for the PING tests with sonic-db-cli

* Updated with a missing , in the database_config.json.j2 file, Do pip install of j2cli in docker-base-buster.

Support load_minigraph command for multi NPU platform

Reverted Add 'interface transceiver' subgroup with 'lpmode' and 'reset'
subcommands (#904) as it dependent of #903 which is not marked to
cherry-pick for 201911. Need to add that before we can use this.

… futures (#4575)

Signed-off-by: Guohan Lu <lguohan@gmail.com>

…4571)

- mgmt buffer issue on 400G port
- high CPU utilization issue caused by some counter reading