make C# docker image in sync with GCE performance workers

src/csharp/global.json

 {
     "sdk": {
-        "version": "1.0.0-preview2-003121"
+        "version": "1.0.0-preview2-003131"
     }
 }
\ No newline at end of file

templates/tools/dockerfile/csharp_dotnetcli_deps.include

 # Install dotnet SDK based on https://www.microsoft.com/net/core#debian
 RUN apt-get update && apt-get install -y curl libunwind8 gettext
-# dotnet-dev-1.0.0-preview2-003121
-RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=809130
+# dotnet-dev-1.0.0-preview2-003131
+RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=827530
 RUN mkdir -p /opt/dotnet && tar zxf dotnet100.tar.gz -C /opt/dotnet
 # dotnet-dev-1.0.1
 RUN curl -sSL -o dotnet101.tar.gz https://go.microsoft.com/fwlink/?LinkID=843453

tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile

@@ -99,8 +99,8 @@ RUN nuget update -self
 
 # Install dotnet SDK based on https://www.microsoft.com/net/core#debian
 RUN apt-get update && apt-get install -y curl libunwind8 gettext
-# dotnet-dev-1.0.0-preview2-003121
-RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=809130
+# dotnet-dev-1.0.0-preview2-003131
+RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=827530
 RUN mkdir -p /opt/dotnet && tar zxf dotnet100.tar.gz -C /opt/dotnet
 # dotnet-dev-1.0.1
 RUN curl -sSL -o dotnet101.tar.gz https://go.microsoft.com/fwlink/?LinkID=843453

tools/dockerfile/test/csharp_coreclr_x64/Dockerfile

@@ -99,8 +99,8 @@ RUN nuget update -self
 
 # Install dotnet SDK based on https://www.microsoft.com/net/core#debian
 RUN apt-get update && apt-get install -y curl libunwind8 gettext
-# dotnet-dev-1.0.0-preview2-003121
-RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=809130
+# dotnet-dev-1.0.0-preview2-003131
+RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=827530
 RUN mkdir -p /opt/dotnet && tar zxf dotnet100.tar.gz -C /opt/dotnet
 # dotnet-dev-1.0.1
 RUN curl -sSL -o dotnet101.tar.gz https://go.microsoft.com/fwlink/?LinkID=843453