Check for GCLatencyMode.NoGCRegion

This test fails occasionaly when run through the automated cake script.  Wrapped the EndNoGCREgion in a check for GCTatencyMode.NoGCRegion to resolve

src/cs/Tests/MonoGame.Extended.Tests/Collections/BagTests.cs

@@ -35,7 +35,12 @@ namespace MonoGame.Extended.Tests.Collections
                     Assert.True(false);
             }
 
-            GC.EndNoGCRegion();
+            //  Wrap in if statement due to exception thrown when running test through
+            //  cake build script or when debugging test script manually.
+            if(GCSettings.LatencyMode == GCLatencyMode.NoGCRegion)
+            {
+                GC.EndNoGCRegion();
+            }
         }
 
     }