chassis: 'show interface portchannel' shows internal portchannels included

[anamehra]

Description

'show interface portchannel' is supposed to display only external portchannels.
'-d all' option is used to display all.

But looks like after #13660 change,
the CLI shows all port channels including the back plane ones without '-d all' option.

Steps to reproduce the issue:

Describe the results you received:

command included internal port channels with back port members.

root@sfd-t2-lc0:/home/admin# show interfaces  portchannel                                            
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,                            
       S - selected, D - deselected, * - not synced                                                  
  No.  Team Dev         Protocol     Ports                                                           
-----  ---------------  -----------  ------------------------------------                            
   **01  PortChannel01    LACP(A)(Dw)  Ethernet-BP232(D) Ethernet-BP236(D)                             
   02  PortChannel02    LACP(A)(Up)  Ethernet-BP244(S) Ethernet-BP240(S)**                                                       
  102  PortChannel102   LACP(A)(Up)  Ethernet0(S) Ethernet8(S)                                       
  104  PortChannel104   LACP(A)(Up)  Ethernet24(S) Ethernet16(S)                                     

Describe the results you expected:

command should not included internal port channels with back port members.

root@sfd-t2-lc0:/home/admin# show interfaces  portchannel                                            
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,                            
       S - selected, D - deselected, * - not synced                                                  
  No.  Team Dev         Protocol     Ports                                                           
-----  ---------------  -----------  ------------------------------------                                                                          
  102  PortChannel102   LACP(A)(Up)  Ethernet0(S) Ethernet8(S)                                       
  104  PortChannel104   LACP(A)(Up)  Ethernet24(S) Ethernet16(S)                                     

Output of show version:

(paste your output here)

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[anamehra]

There is a bug in sonic_py_common/multi_asic.py is_port_channel_internal function.
The function use PORTCHANNEL table to get member port and then test if member ports are internal.
With the new change in portchannel db, members is not an entry in PORTCHANNEL table in config db and thus the function always returns false and all portchannels are included in external list.

The fix is to use PORTCHANNEL_MEMBER table. I am testing a fix.

We can mark this issue dup of #14436

[anamehra]

realized, there is a PR already in process for this. That should fix #14436 as well.