Since bundled plugins will be removed in an upcoming version of Packer,
this commit adds a new warning message whenever a template uses one such
plugin.
This warning has been implemented on build, validate, console and the
inspect subcommands.
In addition to warning about the upcoming change and potential issue
this will cause, this warning message proposes solutions to the user so
they know what they'll have to do in order not to rely on those bundled
plugins later.
This change sets a region on the test datasource config to fix intermittent InvalidAMIID.NotFound errors.
Closes https://github.com/hashicorp/packer-internal-issues/issues/14
Failing results before change
```
> AWS_DEFAULT_REGION=us-west-1 make testacc
=== RUN TestAccInitAndBuildBasicAmazonAmiDatasource
2021/12/07 20:40:05 [INFO] AWS Auth provider used: "SharedCredentialsProvider"
2021/12/07 20:40:05 Found region us-west-1
2021/12/07 20:40:05 [INFO] AWS Auth provider used: "SharedCredentialsProvider"
pluginacc.go:143: Error running plugin acceptance tests: Bad exit code. Logfile: packer_log_amazon-ami_basic_datasource_test.txt
Logs can be found at /Users/wilkenrivera/Development/packer/acctest/plugin/packer_log_amazon-ami_basic_datasource_test.txt
and the acceptance test template can be found at /Users/wilkenrivera/Development/packer/acctest/plugin/amazon-ami_basic_datasource_test.pkr.hcl
--- FAIL: TestAccInitAndBuildBasicAmazonAmiDatasource (9.87s)
FAIL
FAIL github.com/hashicorp/packer/acctest/plugin 10.326s
```
Passing results after change
```
> AWS_DEFAULT_REGION=us-west-1 make testacc
=== RUN TestAccInitAndBuildBasicAmazonAmiDatasource
2021/12/07 20:47:28 [INFO] AWS Auth provider used: "SharedCredentialsProvider"
2021/12/07 20:47:28 Found region us-west-1
2021/12/07 20:47:28 [INFO] AWS Auth provider used: "SharedCredentialsProvider"
--- PASS: TestAccInitAndBuildBasicAmazonAmiDatasource (223.32s)
PASS
```
