[202012 BRCM SAI 4.3.7.0] Pick up fixes and make up BRCM SAI version to 4.3.7.0

[Gfrom2016]

Pick upfollowing fixes and update BRCM SAI to 4.3.7.0:

1. CS00012208537: Add back previous commit 54c5bc4848eb748
2. CS00012253061,SONIC-63280: WB from 3.5 to 4.3, followed by WB to 4.3
3. CS00012207978: SDK-296517, time spent for SAI operations
4. CS00012245601,SONIC-62898: Egress ACL Counted ad Interface TX drops
5. Update pcbb with Fixes for CS00012243699
6. Upgrade on pcbb with Fixes for KB0025353, CS00012221689, CS00012221688, KB0025391, CS00012230519

• commit of "CS00012221688:PFC frames egressing, PFC storm happens simultaneously on 2 ports" is purposely skipped to be picked up later due to SWSS dependency not ready.

Why I did it

How I did it

How to verify it

Tested build target, successful

Manually run these tests after installing sai binary within image 20201231.73 on 7050CX3 (TD3) T0 DUT, all passed.

• vxlan/test_vxlan_decap.py
• fdb/test_fdb.py
• pfcwd/test_pfcwd_all_port_storm.py
• acl/null_route/test_null_route_helper.py
• acl/test_acl.py
• vlan/test_vlan.py
• platform_tests/test_reboot.py

Passed all the SAI T0 automation test case

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205

Description for the changelog

[202012 BRCM SAI 4.3.7.0] Picked up fixes that makes up BRCM SAI version 4.3.7.0

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)

Signed-off-by: zitingguo-ms zitingguo@microsoft.com

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Gfrom2016 / name: zitingguo-ms (65fb866)