COMPMID-1605: API alignment for the MemoryManager with ARMNN

Change-Id: Iac6a95ba7f388e65b7f1c8865c3e9bf289b233ea
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/155490
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: bsgcomp <bsgcomp@arm.com>
diff --git a/arm_compute/runtime/PoolManager.h b/arm_compute/runtime/PoolManager.h
index 5090805..4f0f538 100644
--- a/arm_compute/runtime/PoolManager.h
+++ b/arm_compute/runtime/PoolManager.h
@@ -56,7 +56,9 @@
     IMemoryPool *lock_pool() override;
     void unlock_pool(IMemoryPool *pool) override;
     void register_pool(std::unique_ptr<IMemoryPool> pool) override;
-    size_t num_pools() const override;
+    std::unique_ptr<IMemoryPool> release_pool() override;
+    void                         clear_pools() override;
+    size_t                       num_pools() const override;
 
 private:
     std::list<std::unique_ptr<IMemoryPool>> _free_pools;     /**< List of free pools */