Incorrect data type in FDumpFPSChartToEndpoint::DumpChart()

The TotalTime variable in the FDumpFPSChartToEndpoint::DumpChart() function has recently been changed to int32 when it should be double.

Tested in 4.21.2 (CL - 4753647), 4.22.3 (CL - 7053647), 4.23 (CL - 7273331), 4.24 (CL - 7259848)

1. Create a Blank C++ project
2. Navigate to ChartCreation.cpp
3. Check the DumpChart function

Expected: The type for the TotalTime variable is double

Result: The type is actually converted to int32