Backport import/export spec changes from EE

This backports remaining import/export spec changes from EE to CE.

spec/lib/gitlab/import_export/project_tree_saver_spec.rb

@@ -42,6 +42,10 @@ describe Gitlab::ImportExport::ProjectTreeSaver do
         expect(saved_project_json).to include({ 'description' => 'description', 'visibility_level' => 20 })
       end
 
+      it 'has approvals_before_merge set' do
+        expect(saved_project_json['approvals_before_merge']).to eq(1)
+      end
+
       it 'has milestones' do
         expect(saved_project_json['milestones']).not_to be_empty
       end
@@ -287,7 +291,8 @@ describe Gitlab::ImportExport::ProjectTreeSaver do
                      issues: [issue],
                      snippets: [snippet],
                      releases: [release],
-                     group: group
+                     group: group,
+                     approvals_before_merge: 1
                     )
     project_label = create(:label, project: project)
     group_label = create(:group_label, group: group)

spec/lib/gitlab/import_export/relation_rename_service_spec.rb

@@ -28,6 +28,7 @@ describe Gitlab::ImportExport::RelationRenameService do
 
     before do
       allow(shared).to receive(:export_path).and_return(import_path)
+      allow(ActiveSupport::JSON).to receive(:decode).and_call_original
       allow(ActiveSupport::JSON).to receive(:decode).with(file_content).and_return(json_file)
     end