Update pipeline generation tool to support test variant pipelines (Azure#13177)

Co-authored-by: Wes Haggard <Wes.Haggard@microsoft.com>

Author: azure-sdk

eng/common/pipelines/templates/steps/install-pipeline-generation.yml

@@ -9,7 +9,7 @@ steps:
   - script: >
       dotnet tool install
       Azure.Sdk.Tools.PipelineGenerator
-      --version 1.0.2-dev.20201020.1
+      --version 1.0.2-dev.20210112.1
       --add-source https://pkgs.dev.azure.com/azure-sdk/public/_packaging/azure-sdk/nuget/v3/index.json
       --tool-path ${{parameters.ToolPath}}
     workingDirectory: $(Pipeline.Workspace)/pipeline-generator