IVGCVSW-5636 'Implement NNAPI caching functions'

* Get number of inputs and outputs from optimized network.
* Get number of cached files if backend supports caching.

Signed-off-by: Sadik Armagan <sadik.armagan@arm.com>
Change-Id: Ie02ac123bb7df9b0593a2fe46b5bb564a5994780
diff --git a/src/armnn/OptimizedNetworkImpl.hpp b/src/armnn/OptimizedNetworkImpl.hpp
index d42cff7..112d585 100644
--- a/src/armnn/OptimizedNetworkImpl.hpp
+++ b/src/armnn/OptimizedNetworkImpl.hpp
@@ -21,6 +21,9 @@
 
     virtual profiling::ProfilingGuid GetGuid() const { return m_Guid; };
 
+    virtual size_t GetNumInputs() const;
+    virtual size_t GetNumOutputs() const;
+
     Graph& GetGraph() { return *m_Graph; }
     ModelOptions& GetModelOptions() { return m_ModelOptions; }