Don't submit vk command buffer in updateBackendTexture.

So apparently I did all the work to allow us to not submit in
updateBackendTexture, but then I never actually removed the submit...

Bug: chromium:1087124
Change-Id: Id08a9c5e116cff57dbbeada74186f94da6e28656
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/297866
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tools/DDLPromiseImageHelper.cpp b/tools/DDLPromiseImageHelper.cpp
index 89dca3c..2dba0b9 100644
--- a/tools/DDLPromiseImageHelper.cpp
+++ b/tools/DDLPromiseImageHelper.cpp
@@ -128,6 +128,7 @@
     auto beTex = context->createBackendTexture(&pm, 1, GrRenderable::kNo, GrProtected::kNo,
                                                markFinished, &finishedBECreate);
     if (beTex.isValid()) {
+        context->submit();
         while (!finishedBECreate) {
             context->checkAsyncWorkCompletion();
         }
@@ -175,6 +176,7 @@
                                                         GrRenderable::kNo, GrProtected::kNo,
                                                         markFinished, &finishedBECreate);
         SkASSERT(backendTex.isValid());
+        context->submit();
         while (!finishedBECreate) {
             context->checkAsyncWorkCompletion();
         }