Ignore propagated routes during table import

[richievos]

Similar to how they're ignored when performing a
resourceAwsRouteTableRead.

Relates to #5099

This syncs the continue logic from resourceAwsRouteTableImportState and resourceAwsRouteTableRead. Really these should be using a helper function, but given there's already 3 other places with this code copy-pasted, I wasn't sure what the preferred way of doing this would be. Writing a test for this seems like it'd be pretty difficult, since a full test would require a gateway connected that has routes propagating into it. I assume that's why the existing resourceAwsRouteTableRead doesn't have a comparable test.

Output from test runs below. Apologies I don't have AWS creds in place that I can run this test against. The change proposed here is rather trivial though, and this at least shows it compiles / passes existing normal tests.

$ make test
==> Checking that code complies with gofmt requirements...
go test ./... -timeout=30s -parallel=4
?   	github.com/terraform-providers/terraform-provider-aws	[no test files]
ok  	github.com/terraform-providers/terraform-provider-aws/aws	2.009s

$ make testacc TESTARGS='-run=TestAccAWSAvailabilityZones'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./... -v -run=TestAccAWSAvailabilityZones -timeout 120m
?   	github.com/terraform-providers/terraform-provider-aws	[no test files]
=== RUN   TestAccAWSAvailabilityZones_basic
--- FAIL: TestAccAWSAvailabilityZones_basic (1.44s)
	provider_test.go:75: No valid credential sources found for AWS Provider.
			Please see https://terraform.io/docs/providers/aws/index.html for more information on
			providing credentials for the AWS Provider
=== RUN   TestAccAWSAvailabilityZones_stateFilter
--- FAIL: TestAccAWSAvailabilityZones_stateFilter (0.96s)
	provider_test.go:75: No valid credential sources found for AWS Provider.
			Please see https://terraform.io/docs/providers/aws/index.html for more information on
			providing credentials for the AWS Provider
FAIL
FAIL	github.com/terraform-providers/terraform-provider-aws/aws	2.437s
make: *** [testacc] Error 1

[bflad]

LGTM, thanks for this fix @richievos! 🚀

=== RUN   TestAccAWSRouteTable_panicEmptyRoute
--- PASS: TestAccAWSRouteTable_panicEmptyRoute (9.42s)
=== RUN   TestAccAWSRouteTable_ipv6
--- PASS: TestAccAWSRouteTable_ipv6 (15.32s)
=== RUN   TestAccAWSRouteTable_vgwRoutePropagation
--- PASS: TestAccAWSRouteTable_vgwRoutePropagation (25.96s)
=== RUN   TestAccAWSRouteTable_importBasic
--- PASS: TestAccAWSRouteTable_importBasic (27.57s)
=== RUN   TestAccAWSRouteTable_tags
--- PASS: TestAccAWSRouteTable_tags (30.36s)
=== RUN   TestAccAWSRouteTable_vpcPeering
--- PASS: TestAccAWSRouteTable_vpcPeering (33.27s)
=== RUN   TestAccAWSRouteTableAssociation_basic
--- PASS: TestAccAWSRouteTableAssociation_basic (37.42s)
=== RUN   TestAccAWSRouteTable_basic
--- PASS: TestAccAWSRouteTable_basic (40.67s)
=== RUN   TestAccAWSRouteTable_complex
--- PASS: TestAccAWSRouteTable_complex (157.34s)
=== RUN   TestAccAWSRouteTable_instance
--- PASS: TestAccAWSRouteTable_instance (263.61s)

[bflad]

This has been released in version 1.27.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!