Some report functions have wrong return types for their default response

The service returns a JSON response for requests to /beta//reports/microsoft.graph.getFormsUserActivityUserDetail(period='D7'), yet the CSDL metadata says the function should return an Edm.Stream (file) type:

<Function Name="getFormsUserActivityUserDetail" IsBound="true">
  <Parameter Name="reportRoot" Type="graph.reportRoot" />
  <Parameter Name="date" Type="Edm.Date" Nullable="false" />
  <ReturnType Type="Edm.Stream" Nullable="false" />
</Function>
<Function Name="getFormsUserActivityUserDetail" IsBound="true">
  <Parameter Name="reportRoot" Type="graph.reportRoot" />
  <Parameter Name="period" Type="Edm.String" Nullable="false" Unicode="false" />
  <ReturnType Type="Edm.Stream" Nullable="false" />
</Function>

The response type mismatch leads to generated clients incorrectly handling responses for GET /beta//reports/microsoft.graph.getFormsUserActivityUserDetail(period='D7').

Related to https://github.com/microsoftgraph/msgraph-metadata/issues/223

Start with the CSDL definition for getFormsUserActivityUserDetail and compare both the date and period overloads with the response for the named beta endpoint. Read related issue #223 for context, then verify that the metadata and generated-client interpretation agree on the default response type. Done means the mismatch is corrected and the endpoint is represented as returning Edm.Stream.