Add vksrgb config to dm (Vulkan sRGB). Fix help formatting of vk.

tools/gpu/GrContextFactory.cpp

Index: tools/gpu/GrContextFactory.cpp
diff --git a/tools/gpu/GrContextFactory.cpp b/tools/gpu/GrContextFactory.cpp
index 1b2a08ceabc4144beb5dea1ed12842d8c356810a..151bfd95b33a72e9638f278207bc7b83bf146e14 100644
--- a/tools/gpu/GrContextFactory.cpp
+++ b/tools/gpu/GrContextFactory.cpp
@@ -163,8 +163,7 @@ ContextInfo GrContextFactory::getContextInfo(ContextType type, ContextOptions op
 #ifdef SK_VULKAN
         case kVulkan_GrBackend:
             SkASSERT(kVulkan_ContextType == type);
-            if ((kEnableNVPR_ContextOptions & options) ||
-                (kRequireSRGBSupport_ContextOptions & options)) {
+            if (kEnableNVPR_ContextOptions & options) {
                 return ContextInfo();
             }
             testCtx.reset(CreatePlatformVkTestContext());