Unable to delete an entity in Bing spatial data service data source using __deleteEntity in the xml schema

[Ashtouded]

Repro steps:

1. Create a data source on Bing spatial data services (SDS) and add few entities
2. Create an xml file similar to following to delete an entity

<MainRoot>
  <xs:schema id="shopsBingSDSDataSource_dev" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xs:element name="shopsBingSDSDataSource_dev" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
      <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
          <xs:element name="Shop">
            <xs:complexType>
              <xs:sequence>
                <xs:element name="shopId" type="xs:string" />
                <xs:element name="shopLocation" msdata:DataType="Microsoft.SqlServer.Types.SqlGeography, Microsoft.SqlServer.Types, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" type="xs:anyType" minOccurs="0" />
                <xs:element name="__deleteEntity" type="xs:boolean" minOccurs="0" />
              </xs:sequence>
            </xs:complexType>
          </xs:element>
        </xs:choice>
      </xs:complexType>
      <xs:unique name="Constraint1" msdata:PrimaryKey="true">
        <xs:selector xpath=".//Shop" />
        <xs:field xpath="shopId" />
      </xs:unique>
    </xs:element>
  </xs:schema>  
  <Offering>
    <shopId>8df24e6f-d877-45bd-9256-bc9933d1b154</shopId>
	<shopLocation>POINT (0 0)</shopLocation>    
	<__deleteEntity>true</__deleteEntity>
  </Offering>
</MainRoot>```

3. Use the below method from the toolkit to upload a job (Create a console application to test this. Take reference to the Bing SDS toolkit source code project)
`public async Task<DataflowJob> Upload(DataSource dataSource, LoadOperation loadOperation, bool setPublic, bool skipEmptyLocations)`

Expected: Job on Bing SDS should get created

Actual result: Exception thrown at Line 1440 in Datasource.cs
`var deleteInfo = (string)row[deleteIdx];`

Possible Solution: Use ToString() in above code as follows. This did not give me exception.
`var deleteInfo = row[deleteIdx].ToString();`