Bump Google.Protobuf from 3.9.0-rc1 to 3.15.0 in /XamlBrewer.Uwp.Grpc.Server#1

dependabot[bot] wants to merge 1 commit intomasterXamlBrewer/UWP-gRPC-Sample:masterfrom

dependabot/nuget/XamlBrewer.Uwp.Grpc.Server/Google.Protobuf-3.15.0XamlBrewer/UWP-gRPC-Sample:dependabot/nuget/XamlBrewer.Uwp.Grpc.Server/Google.Protobuf-3.15.0Copy head branch name to clipboard