Update flattening of auto pause notif params in service

[imjaroiswebdev]

New acceptance test case introduced...

==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test $(go list ./... |grep -v 'vendor') -v -count=1 -run TestAccPagerDutyServiceWithAutoPauseNotificationsDisabled_import -timeout 120m
?       github.com/PagerDuty/terraform-provider-pagerduty       [no test files]
?       github.com/PagerDuty/terraform-provider-pagerduty/util/apiutil  [no test files]
=== RUN   TestAccPagerDutyServiceWithAutoPauseNotificationsDisabled_import
--- PASS: TestAccPagerDutyServiceWithAutoPauseNotificationsDisabled_import (15.76s)
PASS
ok      github.com/PagerDuty/terraform-provider-pagerduty/pagerduty     17.236s
testing: warning: no tests to run
PASS
ok      github.com/PagerDuty/terraform-provider-pagerduty/pagerdutyplugin       0.557s [no tests to run]
testing: warning: no tests to run
PASS
ok      github.com/PagerDuty/terraform-provider-pagerduty/util  1.096s [no tests to run]