Add mobile RUM OS types usage fields

[api-clients-generation-pipeline]

See DataDog/datadog-api-spec#720

[zippolyte]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov]

Codecov Report

Merging #629 (8d0a98e) into master (f833d75) will decrease coverage by 0.11%.
The diff coverage is 4.19%.

Impacted Files	Coverage Δ
api/v1/datadog/model_usage_rum_sessions_hour.go	0.00% <0.00%> (ø)
api/v1/datadog/model_usage_summary_date_org.go	3.34% <0.00%> (-0.35%)	⬇️
api/v1/datadog/model_usage_summary_date.go	4.05% <7.69%> (+0.37%)	⬆️
api/v1/datadog/model_usage_summary_response.go	3.39% <7.69%> (+0.38%)	⬆️
api/v2/datadog/model_permission_attributes.go	0.00% <0.00%> (-14.96%)	⬇️
api/v2/datadog/model_permission.go	1.81% <0.00%> (-14.55%)	⬇️
...pi/v2/datadog/model_user_response_included_item.go	20.00% <0.00%> (-7.70%)	⬇️
api/v2/datadog/model_roles_type.go	21.42% <0.00%> (-3.58%)	⬇️
api/v1/datadog/api_aws_integration.go	45.52% <0.00%> (-0.63%)	⬇️