[config engine] For l2 preset, use admin_status: up by default (#3902)

Updated the l2 preset config generator to specify 'admin_status': 'up' for every port by default.
The use of setdefault() ensures that if port already has some admin_status set, the original value will not be overwritten.

Signed-off-by: Mykola Faryma <mykolaf@mellanox.com>

src/sonic-config-engine/config_samples.py

@@ -51,6 +51,7 @@ def generate_l2_config(data):
     data['VLAN']['Vlan1000'].setdefault('members', vp)
     data['VLAN_MEMBER'] = {}
     for port in natsorted(data['PORT'].keys()):
+        data['PORT'][port].setdefault('admin_status', 'up')
         data['VLAN_MEMBER']['Vlan1000|{}'.format(port)] = {'tagging_mode': 'untagged'}
     return data