Add GLES unit tests to Kokoro Windows CI

This required disabling the popup dialog which waits for a debugger to
be attached. This is achieved by setting an environment variable:
SWIFTSHADER_DISABLE_DEBUGGER_WAIT_DIALOG=1

Bug b/123360006

Change-Id: Ic1269fdae3088b08a85322cbc7e33a3bdd8292cb
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27548
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Stephen White <senorblanco@chromium.org>
Reviewed-by: Alexis Hétu <sugoi@google.com>
diff --git a/src/Vulkan/main.cpp b/src/Vulkan/main.cpp
index 80b6ee0..9a75f05 100644
--- a/src/Vulkan/main.cpp
+++ b/src/Vulkan/main.cpp
@@ -62,9 +62,17 @@
 	switch(reason)
 	{
 	case DLL_PROCESS_ATTACH:
-#ifdef DEBUGGER_WAIT_DIALOG
-		WaitForDebugger(instance);
-#endif
+		#ifdef DEBUGGER_WAIT_DIALOG
+		{
+			char disable_debugger_wait_dialog[] = "0";
+			GetEnvironmentVariable("SWIFTSHADER_DISABLE_DEBUGGER_WAIT_DIALOG", disable_debugger_wait_dialog, sizeof(disable_debugger_wait_dialog));
+
+			if(disable_debugger_wait_dialog[0] != '1')
+			{
+				WaitForDebugger(instance);
+			}
+		}
+		#endif
 		break;
 	case DLL_THREAD_ATTACH:
 	case DLL_THREAD_DETACH: