Add option to enable AWS s3 versioning

[ronakbanka]

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To speed up the process of reviewing your pull request please provide us with:

• A short explanation of the proposed change:

  This PR adds option enable_s3_versioning to enable versioning for AWS s3 buckets using terraform templates.

• An explanation of the use cases your change solves:

  BBR backups support both versioned and unversioned s3 buckets, to enable versioning it adds a manual task to enable versioning for each bucket from UI/ AWS cli.

  Using this flag in pipeline will save that additional manual task time.

• Expected result after the change: By default versioning will be disabled, can be switched using the flag.

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An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  ~ aws_s3_bucket.bosh
      versioning.0.enabled: "false" => "true"

  ~ aws_s3_bucket.buildpacks
      versioning.0.enabled: "false" => "true"

  ~ aws_s3_bucket.droplets
      versioning.0.enabled: "false" => "true"

  ~ aws_s3_bucket.packages
      versioning.0.enabled: "false" => "true"

  ~ aws_s3_bucket.resources
      versioning.0.enabled: "false" => "true"

Plan: 0 to add, 5 to change, 0 to destroy.

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• Current result before the change:

  Versioning is disabled by default for all buckets

• Links to any other associated PRs or issues:

• [x] I have viewed signed and have submitted the Contributor License Agreement

• [x] I have made this pull request to the master branch

• [x] I have run all the unit tests

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