Ensure ECS deployment allow JSON file config

[khanhtc1202]

What this PR does / why we need it:

Add test to ensure the current ECS deployment allows configuration in JSON format.

Which issue(s) this PR fixes:

Fixes #1686 #1687

Does this PR introduce a user-facing change?:

NONE

[pipecd-bot]

Code coverage for golang is 32.57%. This pull request decreases coverage by -0.36%.

File	Function	Base	Head	Diff
pkg/app/piped/cloudprovider/ecs/client.go	newClient	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.CreateService	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.UpdateService	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.RegisterTaskDefinition	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.CreateTaskSet	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.GetPrimaryTaskSet	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.DeleteTaskSet	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.UpdateServicePrimaryTaskSet	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.ServiceExists	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.GetListener	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.getLoadBalancerArn	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/client.go	client.ModifyListener	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/ecs.go	LoadServiceDefinition	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/ecs.go	LoadTaskDefinition	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/ecs.go	LoadTargetGroups	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/ecs.go	registry.Client	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/ecs.go	DefaultRegistry	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/service.go	loadServiceDefinition	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/service.go	parseServiceDefinition	--	78.57%	+78.57%
pkg/app/piped/cloudprovider/ecs/service.go	parseServiceDefinitionForCluster	--	75.00%	+75.00%
pkg/app/piped/cloudprovider/ecs/service.go	parseServiceDefinitionForRole	--	75.00%	+75.00%
pkg/app/piped/cloudprovider/ecs/target_groups.go	loadTargetGroups	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/task.go	loadTaskDefinition	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/task.go	parseTaskDefinition	--	75.00%	+75.00%
pkg/app/piped/cloudprovider/ecs/task.go	FindImageTag	--	0.00%	+0.00%
pkg/app/piped/cloudprovider/ecs/task.go	parseContainerImage	--	0.00%	+0.00%

[nghialv]

Those tasks should be closed once this PR got merged.
https://github.com/pipe-cd/pipe/issues?q=is%3Aissue+is%3Aopen+loading

[nghialv]

/lgtm

[nakabonne]

👍
/approve

[pipecd-bot]

This pull request is APPROVED by nakabonne.

Approvers can cancel the approval by writing /approve cancel in a comment. Any additional commits also will change this pull request to be not-approved.