IVGCVSW-2353 Ignore control inputs in TensorFlow parser

 * Allow control inputs from TensorFlow graph but ignore them in ArmNN graph.
 * Add utility function to test ArmNN graph structure.
 * Add ArmNN graph structure tests in TensorFlow paresr to ensure that control inputs
   are ignored in ArmNN graph as well as their inputs that are not used anywhere else.

Change-Id: Ib0ea0d2df85e3fc79b748fa4c9d20e0649352bc1
diff --git a/Android.mk b/Android.mk
index ad8026a..4c8c492 100644
--- a/Android.mk
+++ b/Android.mk
@@ -215,6 +215,7 @@
         src/armnn/test/EndToEndTest.cpp \
         src/armnn/test/UtilsTests.cpp \
         src/armnn/test/GraphTests.cpp \
+        src/armnn/test/GraphUtils.cpp \
         src/armnn/test/RuntimeTests.cpp \
         src/armnn/test/SubGraphTests.cpp \
         src/armnn/test/TensorTest.cpp \