Remove enum from legend_size

[api-clients-generation-pipeline]

See DataDog/datadog-api-spec#515

[therve]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov]

Codecov Report

Merging #418 into master will increase coverage by 0.11%.
The diff coverage is n/a.

Impacted Files	Coverage Δ	Complexity Δ
.../v1/client/model/DistributionWidgetDefinition.java	55.40% <ø> (ø)	25.00 <0.00> (ø)
...g/api/v1/client/model/HeatMapWidgetDefinition.java	59.13% <ø> (ø)	32.00 <0.00> (ø)
.../v1/client/model/SyntheticsDeleteTestsPayload.java	19.23% <ø> (ø)	3.00 <0.00> (ø)
...pi/v1/client/model/TimeseriesWidgetDefinition.java	59.04% <ø> (ø)	35.00 <0.00> (ø)
.../datadog/api/v1/client/model/WidgetDefinition.java	64.45% <ø> (ø)	50.00 <0.00> (ø)
...om/datadog/api/v1/client/api/UsageMeteringApi.java	88.04% <0.00%> (+0.48%)	45.00% <0.00%> (ø%)
.../client/model/UsageSpecifiedCustomReportsMeta.java	14.28% <0.00%> (+14.28%)	2.00% <0.00%> (+2.00%)
.../client/model/UsageSpecifiedCustomReportsPage.java	14.28% <0.00%> (+14.28%)	2.00% <0.00%> (+2.00%)
.../client/model/UsageSpecifiedCustomReportsData.java	22.22% <0.00%> (+22.22%)	4.00% <0.00%> (+4.00%)
...t/model/UsageSpecifiedCustomReportsAttributes.java	22.95% <0.00%> (+22.95%)	7.00% <0.00%> (+7.00%)
... and 1 more