[coverity] Fix 1566348 Uninitialized scalar field

Default initialize the `enableParameterValidation` and
`enableLeakChecking` data members of the
`ur_validation_layer::context_t` object.

Author: kbenzie

source/loader/layers/validation/ur_validation_layer.hpp

@@ -20,8 +20,8 @@ namespace ur_validation_layer {
 ///////////////////////////////////////////////////////////////////////////////
 class __urdlllocal context_t : public proxy_layer_context_t {
   public:
-    bool enableParameterValidation;
-    bool enableLeakChecking;
+    bool enableParameterValidation = false;
+    bool enableLeakChecking = false;
     logger::Logger logger;
 
     ur_dditable_t urDdiTable = {};