Update docker-sonic-mgmt to buster (#13287)

Why I did it
docker-sonic-mgmt build is failing.

How I did it
stretch docker is disabled recently. Update docker-sonic-mgmt to buster.
Migrate from sonictest to sonicbld. Because Azure requires migrate vm from uswest2 to uswest3.
Fix a build issue when build image.
How to verify it

.azure-pipelines/docker-sonic-mgmt.yml

@@ -32,17 +32,18 @@ stages:
 - stage: Build
   jobs:
   - job: Build
-    pool: sonictest
+    pool: sonicbld
     timeoutInMinutes: 360
     steps:
     - template: cleanup.yml
     - checkout: self
       clean: true
-      submodules: recursive
     - bash: |
         set -xe
-        make configure PLATFORM=generic
-        make target/docker-sonic-mgmt.gz
+        git submodule update --init --recursive -- src/sonic-platform-daemons src/sonic-genl-packet src/sonic-sairedis src/ptf src/sonic-device-data
+
+        make SONIC_BUILD_JOBS=$(nproc) DEFAULT_CONTAINER_REGISTRY=publicmirror.azurecr.io ENABLE_DOCKER_BASE_PULL=y configure PLATFORM=generic
+        make SONIC_BUILD_JOBS=$(nproc) DEFAULT_CONTAINER_REGISTRY=publicmirror.azurecr.io ENABLE_DOCKER_BASE_PULL=y target/docker-sonic-mgmt.gz
         cp target -r $(Build.ArtifactStagingDirectory)/target
         docker load -i target/docker-sonic-mgmt.gz
         docker tag docker-sonic-mgmt $REGISTRY_SERVER/docker-sonic-mgmt:latest

rules/docker-sonic-mgmt.mk

@@ -3,4 +3,3 @@ DOCKER_SONIC_MGMT = docker-sonic-mgmt.gz
 $(DOCKER_SONIC_MGMT)_PATH = $(DOCKERS_PATH)/docker-sonic-mgmt
 $(DOCKER_SONIC_MGMT)_DEPENDS += $(SONIC_DEVICE_DATA) $(PTF)
 SONIC_DOCKER_IMAGES += $(DOCKER_SONIC_MGMT)
-SONIC_STRETCH_DOCKERS += $(DOCKER_SONIC_MGMT)

src/sonic-build-hooks/scripts/buildinfo_base.sh

@@ -21,6 +21,7 @@ else
 	PKG_CACHE_PATH=/sonic/target/vcache/${IMAGENAME}
 fi
 PKG_CACHE_FILE_NAME=${PKG_CACHE_PATH}/cache.tgz
+sudo chown $USER $(dirname $PKG_CACHE_PATH)
 mkdir -p ${PKG_CACHE_PATH}
 
 . ${BUILDINFO_PATH}/scripts/utils.sh