COMPMID-1478: Stop relying on static default OpenCL objects in cl2.hpp

This causes problems when ACL is used as a shared library on Android.
Fixes some problems related to creation / destruction order between the Graph's CL backend and core / runtime

Change-Id: I716d63fd42f4586df1ffbb6fa97e4db06d3a781b
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/143228
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele DiGiorgio <michele.digiorgio@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
diff --git a/src/core/CL/kernels/CLDepthwiseConvolutionLayer3x3NCHWKernel.cpp b/src/core/CL/kernels/CLDepthwiseConvolutionLayer3x3NCHWKernel.cpp
index e091e5c..a40aa28 100644
--- a/src/core/CL/kernels/CLDepthwiseConvolutionLayer3x3NCHWKernel.cpp
+++ b/src/core/CL/kernels/CLDepthwiseConvolutionLayer3x3NCHWKernel.cpp
@@ -280,7 +280,7 @@
 
     auto win_config = validate_and_configure_window(input->info(), weights->info(), output->info(), conv_info, depth_multiplier, gpu_target, kernel_name);
     ARM_COMPUTE_ERROR_THROW_ON(win_config.first);
-    ICLKernel::configure(win_config.second);
+    ICLKernel::configure_internal(win_config.second);
 
     _kernel = static_cast<cl::Kernel>(CLKernelLibrary::get().create_kernel(kernel_name, build_opts.options()));
 
@@ -345,7 +345,7 @@
         add_3D_tensor_argument(idx, _output, slice_out);
         add_3D_tensor_argument(idx, _weights, slice_weights);
 
-        enqueue(queue, *this, slice_out, _lws_hint);
+        enqueue(queue, *this, slice_out, lws_hint());
     }
     while(window.slide_window_slice_3D(slice_out) && win_in.slide_window_slice_3D(slice_in));
 }