Support for arm64 in enas-cnn-cifar10 image

[tenzen-y]

Signed-off-by: tenzen-y yuki.iwai.tz@gmail.com

What this PR does / why we need it:
I modified Dockerfile for enas-cnn-cifar10 image to support arm64 and I tested operations in the below commands:

$ # For arm64
$ docker run -it --platform linux/arm64 ytenzen/multiplatform-enas-cnn-cifar10-gpu:latest  --num_gpus=0 --num_epochs=1 --architecture="[[49]]" --nn_config="{'num_layers': 1, 'input_sizes': [32, 32, 3], 'output_sizes': [10], 'embedding': {'49': {'opt_id': 49, 'opt_type': 'separable_convolution', 'opt_params': {'filter_size': '3', 'num_filter': '128', 'stride': '2', 'depth_multiplier': '2'}}}}"
$ # For amd64
$ docker run -it --platform linux/amd64 ytenzen/multiplatform-enas-cnn-cifar10-gpu:latest  --num_gpus=0 --num_epochs=1 --architecture="[[49]]" --nn_config="{'num_layers': 1, 'input_sizes': [32, 32, 3], 'output_sizes': [10], 'embedding': {'49': {'opt_id': 49, 'opt_type': 'separable_convolution', 'opt_params': {'filter_size': '3', 'num_filter': '128', 'stride': '2', 'depth_multiplier': '2'}}}}"

Also, I fixed a bug in TARGETARCH for enas-cnn-cifar10 and tf-mnist-with-summaries images.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Part-of #1900

Checklist:

• Docs included if any changes are user facing

[coveralls]

Coverage decreased (-0.1%) to 73.431% when pulling 7d4f487 on tenzen-y:support-for-arm64-in-enas-image into 6870587 on kubeflow:master.

[anencore94]

/lgtm 👍

[johnugeorge]

/approve

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: johnugeorge, tenzen-y

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [johnugeorge]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[tenzen-y]

@johnugeorge Can you also add /lgtm to this PR?

[johnugeorge]

/lgtm

[tenzen-y]

Thanks! @johnugeorge