vulkan-cereal: Use ctx_id when working with blobs

Having a single, host wide blob id namespace creates
a few problems.  One problem is when using guest
generated blob ids, it's not possible to know which
client generated it.  Guest generated IDs enable a
few features, such as deferred mapping.

BUG=280064176
TEST=launch_cvd --gpu_mode=gfxstream_guest_angle

Change-Id: I9ba2d9846256b2b3758e727b29486c034be54646
diff --git a/stream-servers/RenderThread.cpp b/stream-servers/RenderThread.cpp
index 90a3bd7..d014795 100644
--- a/stream-servers/RenderThread.cpp
+++ b/stream-servers/RenderThread.cpp
@@ -460,6 +460,7 @@
             // Note: It's risky to limit Vulkan decoding to one thread,
             // so we do it outside the limiter
             if (tInfo.m_vkInfo) {
+                tInfo.m_vkInfo->ctx_id = mContextId;
                 VkDecoderContext context = {
                     .processName = processName,
                     .gfxApiLogger = &gfxLogger,