tests/data-source/aws_pricing_product: Add capacitystatus filter for EC2 test configuration
tests/data-source/aws_pricing_product: Add capacitystatus filter for EC2 test configuration

The Pricing API is now returning multiple product results without specifying a particular capacity filter. Seems releated to the recently added EC2 Capacity Reservations.

Previous output from acceptance testing:

```
--- FAIL: TestAccDataSourceAwsPricingProduct_ec2 (2.10s)
    testing.go:538: Step 0 error: Error refreshing: 1 error occurred:
        	* data.aws_pricing_product.test: 1 error occurred:
        	* data.aws_pricing_product.test: data.aws_pricing_product.test: Pricing product query not precise enough. Returned more than one element: [{"product": ... big JSON blob ...
```

Output from acceptance testing:

```
--- PASS: TestAccDataSourceAwsPricingProduct_redshift (6.80s)
--- PASS: TestAccDataSourceAwsPricingProduct_ec2 (6.84s)
```

terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,Ninir/terraform-provider-aws,Ninir/terraform-provider-aws,terraform-providers/terraform-provider-aws,Ninir/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,Ninir/terraform-provider-aws