Fix dotnet installation selection on Linux to favor lib over share

Author: mafiesto4

Source/Tools/Flax.Build/Build/DotNet/DotNetSdk.cs

@@ -199,7 +199,11 @@ public DotNetSdk()
                 if (rid == ridFallback)
                     ridFallback = "";
                 if (string.IsNullOrEmpty(dotnetPath))
-                    dotnetPath = "/usr/share/dotnet/";
+                {
+                    dotnetPath = "/usr/lib/dotnet/";
+                    if (!Directory.Exists(dotnetPath))
+                        dotnetPath = "/usr/share/dotnet/";
+                }
                 break;
             }
             case TargetPlatform.Mac: