Check if Vulkan layers have a valid looking GIPA

Bug: 137862180

Test: flash, remove vkGetInstanceProcAddr from layer symbols, run

Change-Id: I4d4d75585623d2c15c57b4d8ad0243a2fc347fce
diff --git a/vulkan/libvulkan/api.cpp b/vulkan/libvulkan/api.cpp
index 71048db..368130d 100644
--- a/vulkan/libvulkan/api.cpp
+++ b/vulkan/libvulkan/api.cpp
@@ -664,6 +664,12 @@
         return VK_ERROR_LAYER_NOT_PRESENT;
     }
 
+    if (!layer.ref.GetGetInstanceProcAddr()) {
+        ALOGW("Failed to locate vkGetInstanceProcAddr in layer %s", name);
+        layer.ref.~LayerRef();
+        return VK_ERROR_LAYER_NOT_PRESENT;
+    }
+
     ALOGI("Loaded layer %s", name);
 
     return VK_SUCCESS;