[yang-models] sonic-mirror-session.yang miss policer leaf

[wen587]

Description

sonic-mirror-session.yang doesn't support policer where it is needed for rate limit

Steps to reproduce the issue:

1. Sample mirror session config contains policer.

admin@vlab-01:~/everflow$ cat session.json
{
  "MIRROR_SESSION": {
    "mirror_session_dscp": {
    "dscp": "5",
    "dst_ip": "2.2.2.2",
    "policer": "everflow_static_policer",
    "src_ip": "1.1.1.1",
    "ttl": "64",
    "type": "ERSPAN"
    }
  }
}

Describe the results you received:

Describe the results you expected:

We need to add Yang model for policer first then add the leaf for sonic-mirror-session.yang.

Output of show version:

admin@vlab-01:~/everflow$ show ver

SONiC Software Version: SONiC.master.58770-6402a0226
Distribution: Debian 11.1
Kernel: 5.10.0-8-2-amd64
Build commit: 6402a0226
Build date: Mon Dec 13 09:02:14 UTC 2021
Built by: AzDevOps@sonic-build-workers-000Z9S

Platform: x86_64-kvm_x86_64-r0
HwSKU: Force10-S6000
ASIC: vs
ASIC Count: 1
Serial Number: N/A
Model Number: N/A
Hardware Revision: N/A
Uptime: 08:30:18 up  2:47,  2 users,  load average: 0.21, 0.35, 0.27

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):

[wen587]

POLICER yang missing should be solved first to fix above issue.
#9742

[zhangyanzhao]

@rupesh-k can you please help to take a look? Thanks.