Add the execution policy when running powershell in size on disk benchmarks (#20680)

Since moving to the helix queue, we have been failing because the execution policy on the vms is not set to unrestricted. To get around this, we need to explicitly pass -ExecutionPolicy Bypass.

Author: michellemcdaniel

tests/src/sizeondisk/sodbench/SoDBench.cs

@@ -431,7 +431,7 @@ private static void InstallSharedRuntime()
             var psi = new ProcessStartInfo() {
                 WorkingDirectory = s_sandboxDir.FullName,
                 FileName = @"powershell.exe",
-                Arguments = $"-NoProfile .\\Dotnet-Install.ps1 -Runtime dotnet -InstallDir .dotnet -Channel {s_dotnetChannel} -Architecture {s_targetArchitecture}"
+                Arguments = $"-NoProfile -ExecutionPolicy Bypass -File .\\Dotnet-Install.ps1 -Runtime dotnet -InstallDir .dotnet -Channel {s_dotnetChannel} -Architecture {s_targetArchitecture}"
             };
             LaunchProcess(psi, 180000);
         }
@@ -441,7 +441,7 @@ private static void InstallDotnet()
             var psi = new ProcessStartInfo() {
                 WorkingDirectory = s_sandboxDir.FullName,
                 FileName = @"powershell.exe",
-                Arguments = $"-NoProfile .\\Dotnet-Install.ps1 -InstallDir .dotnet -Channel {s_dotnetChannel} -Architecture {s_targetArchitecture}"
+                Arguments = $"-NoProfile -ExecutionPolicy Bypass -File .\\Dotnet-Install.ps1 -InstallDir .dotnet -Channel {s_dotnetChannel} -Architecture {s_targetArchitecture}"
             };
             LaunchProcess(psi, 180000);
         }