Update benchmark app branches to use grpc-dotnet (#935)

Author: JamesNK

perf/benchmarkapps/GrpcAspNetCoreServer/grpc-aspnetcore-server.yml

@@ -1,8 +1,8 @@
 jobs:
   grpcAspNetCoreServer:
     source:
-      repository: https://github.com/JamesNK/grpc-dotnet
-      branchOrCommit: jamesnk/benchmarch-grpcclient
+      repository: https://github.com/grpc/grpc-dotnet.git
+      branchOrCommit: master
       project: perf/benchmarkapps/GrpcAspNetCoreServer/GrpcAspNetCoreServer.csproj
     readyStateText: Application started
     waitForExit: false

perf/benchmarkapps/GrpcClient/grpc-client.yml

@@ -1,8 +1,8 @@
 jobs:
   grpcDotNetClient:
     source:
-      repository: https://github.com/jamesnk/grpc-dotnet.git
-      branchOrCommit: jamesnk/benchmarch-grpcclient
+      repository: https://github.com/grpc/grpc-dotnet.git
+      branchOrCommit: master
       project: perf/benchmarkapps/GrpcClient/GrpcClient.csproj
     readyStateText: gRPC Client
     sdkVersion: 3.1.102

perf/benchmarkapps/GrpcCoreServer/grpc-core-server.yml

@@ -1,8 +1,8 @@
 jobs:
   grpcCoreServer:
     source:
-      repository: https://github.com/jamesnk/grpc-dotnet.git
-      branchOrCommit: jamesnk/benchmarch-grpcclient
+      repository: https://github.com/grpc/grpc-dotnet.git
+      branchOrCommit: master
       project: perf/benchmarkapps/GrpcCoreServer/GrpcCoreServer.csproj
     readyStateText: Application started
     waitForExit: false