layers: Rename param_checker to parameter_validation

Also, param_check.h -> parameter_validation.h and .json files changed.

Change-Id: I9db10563bcc2640fe6b90588d3c80c4fe50a8a83
diff --git a/loader/loader.h b/loader/loader.h
index ae51725..b0b3663 100644
--- a/loader/loader.h
+++ b/loader/loader.h
@@ -83,7 +83,7 @@
 static const char UTF8_DATA_BYTE_MASK = 0xC0;
 
 static const char std_validation_names[8][VK_MAX_EXTENSION_NAME_SIZE] = {
-    "VK_LAYER_GOOGLE_threading",     "VK_LAYER_LUNARG_param_checker",
+    "VK_LAYER_GOOGLE_threading",     "VK_LAYER_LUNARG_parameter_validation",
     "VK_LAYER_LUNARG_device_limits", "VK_LAYER_LUNARG_object_tracker",
     "VK_LAYER_LUNARG_image",         "VK_LAYER_LUNARG_core_validation",
     "VK_LAYER_LUNARG_swapchain",     "VK_LAYER_GOOGLE_unique_objects"};