gfxstream: Replace GuestUsesAngle nomenclature with GuestVulkanOnly.

As this flag now applies with Linux+Zink as the GL translation as well.

Change-Id: I8f648ebe845a251f7c32479ad7bf87ee02a14ce3
diff --git a/host/RenderThread.cpp b/host/RenderThread.cpp
index 2f5aa3a..8a83803 100644
--- a/host/RenderThread.cpp
+++ b/host/RenderThread.cpp
@@ -273,7 +273,7 @@
     //
     // initialize decoders
 #if GFXSTREAM_ENABLE_HOST_GLES
-    if (!FrameBuffer::getFB()->getFeatures().GuestUsesAngle.enabled) {
+    if (!FrameBuffer::getFB()->getFeatures().GuestVulkanOnly.enabled) {
         tInfo.initGl();
     }