[docker-sonic-vs] Install sonic-platform-common package (#6587)

**- Why I did it**

sonic-utilities will become dependent upon sonic-platform-common as of sonic-net/sonic-utilities#1386.

**- How I did it**

- Add sonic-platform-common as a dependency in docker-sonic-vs.mk
- Additionally, no longer install Python 2 packages of swsssdk and sonic-py-common, as they should no longer be needed.

platform/vs/docker-sonic-vs.mk

@@ -18,10 +18,9 @@ $(DOCKER_SONIC_VS)_DEPENDS += $(SWSS) \
 
 # swsssdk is a dependency of sonic-py-common
 # TODO: sonic-py-common should depend on swsscommon instead
-$(DOCKER_SONIC_VS)_PYTHON_WHEELS += $(SWSSSDK_PY2) \
-                                    $(SWSSSDK_PY3) \
-                                    $(SONIC_PY_COMMON_PY2) \
+$(DOCKER_SONIC_VS)_PYTHON_WHEELS += $(SWSSSDK_PY3) \
                                     $(SONIC_PY_COMMON_PY3) \
+                                    $(SONIC_PLATFORM_COMMON_PY3) \
                                     $(SONIC_YANG_MODELS_PY3) \
                                     $(SONIC_YANG_MGMT_PY3) \
                                     $(SONIC_UTILITIES_PY3) \