Fix controller environment

[turkenh]

Description of your changes

Currently installations from master branch fails with the following logs:

crossplane-provider: error: required flag --terraform-version not provided, try --help

This PR fixes this issue by passing the required environment to the controller at runtime. It also set DOCKER_REGISTRY only if not set to be able to test locally built image.

As reported by a community member on slack.

I have:

• [x] Read and followed Crossplane's contribution process.
• [x] Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

Installed the controller using a provider image from this PR.