Add sonic_py_common dependency for docker-gnmi-sidecar

The sidecar uses sonic_py_common.sidecar_common library which needs
to be explicitly installed as a Python wheel. This mirrors the fix
in PR sonic-net#25225 for docker-telemetry-sidecar.

Signed-off-by: Dawei Huang <daweihuang@microsoft.com>

Author: hdwhdw

rules/docker-gnmi-sidecar.mk

@@ -21,6 +21,9 @@ SONIC_INSTALL_DOCKER_DBG_IMAGES += $(DOCKER_GNMI_SIDECAR_DBG)
 
 
 $(DOCKER_GNMI_SIDECAR)_DEPENDS += $(LIBSWSSCOMMON)
+
+$(DOCKER_GNMI_SIDECAR)_INSTALL_PYTHON_WHEELS = $(SONIC_PY_COMMON_PY3)
+
 $(DOCKER_GNMI_SIDECAR)_INSTALL_DEBS = $(LIBSWSSCOMMON) \
                                        $(PYTHON3_SWSSCOMMON) \
                                        $(LIBYANG_PY3)