[ECS] [BUG] gRPC load balancer does not work

[mostafafarzaneh]

Summary
Service Connect failed to distribute traffic between the two services correctly when using gRPC

Description
We utilize gRPC for communication between two services: Service A (client) and Service B (server), with Service B running multiple instances for scalability.
Under AppMesh, load balancing across these instances was effective. However, since migrating to Service Connect, all traffic from Service A is directed to a single instance of Service B, bypassing the expected load distribution.

Expected Behavior
Service Connect should distribute traffic across all instances of Service B similarly to how AppMesh did.

Observed Behavior
All traffic is routed to only one instance of Service B, leading to potential performance bottlenecks.

Environment Details
We are using AWS ECS with fargate.