spec: don't run GraphQL audit log spec without dynamo

`before(:once)` gets run _before_ `before(:each)` blocks, so it was
still running and failing if dynamo isn't configured

Change-Id: Ic79aabecf1146f7f49125f56b2c53da94127f907
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/358305
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Jacob Burroughs <jburroughs@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>

spec/graphql/mutation_audit_log_spec.rb

@@ -29,6 +29,8 @@ describe AuditLogFieldExtension do
   end
 
   before(:once) do
+    next unless AuditLogFieldExtension.enabled?
+
     creds = Aws::Credentials.new("key", "secret")
     Canvas::DynamoDB::DevUtils.initialize_ddb_for_development!(:auditors, "graphql_mutations", recreate: true, credentials: creds)
     course_with_student(active_all: true)
@@ -91,6 +93,8 @@ describe AuditLogFieldExtension::Logger do
   let(:mutation) { double(graphql_name: "asdf") }
 
   before(:once) do
+    next unless AuditLogFieldExtension.enabled?
+
     WebMock.enable_net_connect!
     creds = Aws::Credentials.new("key", "secret")
     Canvas::DynamoDB::DevUtils.initialize_ddb_for_development!(:auditors, "graphql_mutations", recreate: true, credentials: creds)
@@ -121,6 +125,12 @@ describe AuditLogFieldExtension::Logger do
   end
 
   context "#log_entry_ids" do
+    before do
+      unless AuditLogFieldExtension.enabled?
+        skip("AuditLog needs to be enabled by configuring dynamodb.yml")
+      end
+    end
+
     it "uses #asset_string and includes the domain_root_account id for the object_id" do
       logger = AuditLogFieldExtension::Logger.new(mutation, {}, { input: {} })
       expect(logger.log_entry_ids(@entry, "some_field")).to eq ["#{@course.root_account.global_id}-assignment_#{@entry.id}"]