*Why I did it
The current sonic image bringup failed on Silverstone:
4:56:15.957705 sonic NOTICE swss#orchagent: :- addDecapTunnel: Create overlay loopback router interface oid:6000000000520
*How I did it
Enable bcm switch Tunnel function on Silverstone.
*How to verify it
The new sonic image can bringup OK on Silverstone.
However in SAI 3.7 default behaviout got changes to 128 Group and 128
Memeber each.
This change is to make sure we are using same ECMP Group/Memeber Per
Group for 3.7 also so that behaviour is consistent.
Signed-off-by: Abhishek Dosi <abdosi@microsoft.com>