Optimize enclave manager docker image

[manju956]

Avalon workflow is broken in SGX HW mode. Following SGX error is observed during enclave initialization. failed to initialize enclave; Failed to get SGX quote size.: UNKNOWN SGX ERROR:<error_value>

This issue is observed since changes to containerizing enclave manager was introduced. Also, the issue is due to some discrepancy in final image of enclave manager dockerfile. As a temporary workaround, final image is removed in the source code so that all binaries and environement will be available in build image of dockerfile itself.

AI:

1. Identify the discrepancy in final stage which i causing SGX error during initialization and fix it.
2. Bring back optimizations that was done in the final stage of the docker image.