Add xrDestroySession to fake_openxr version of xrGetInstanceProcAddr

Lack of xrDestroySession entry in xrGetInstanceProcAddr was causing
calls to xrDestroySession in code to crash and make it difficult
to debug XR tests.

This CL adds an entry for xrDestroySession.

Change-Id: Ib6cfe2a5181fb328409ab54e60284da1cfb816e9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2561297Reviewed-by: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Rafael Cintron <rafael.cintron@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#831169}

device/vr/openxr/test/fake_openxr_impl_api.cc

@@ -938,6 +938,8 @@ XrResult XRAPI_PTR xrGetInstanceProcAddr(XrInstance instance,
     *function = reinterpret_cast<PFN_xrVoidFunction>(xrDestroyActionSet);
   } else if (strcmp(name, "xrDestroyInstance") == 0) {
     *function = reinterpret_cast<PFN_xrVoidFunction>(xrDestroyInstance);
+  } else if (strcmp(name, "xrDestroySession") == 0) {
+    *function = reinterpret_cast<PFN_xrVoidFunction>(xrDestroySession);
   } else if (strcmp(name, "xrDestroySpace") == 0) {
     *function = reinterpret_cast<PFN_xrVoidFunction>(xrDestroySpace);
   } else if (strcmp(name, "xrEndFrame") == 0) {