IVGCVSW-2696 Serialize / de-serialize the Mean layer

Change-Id: Iee4bab5a6d6b992cf4bba8697a2918f854c906a3
Signed-off-by: Sadik Armagan <sadik.armagan@arm.com>
diff --git a/src/armnnSerializer/ArmnnSchema.fbs b/src/armnnSerializer/ArmnnSchema.fbs
index ac32e66..01142ff 100644
--- a/src/armnnSerializer/ArmnnSchema.fbs
+++ b/src/armnnSerializer/ArmnnSchema.fbs
@@ -109,7 +109,8 @@
     ResizeBilinear = 25,
     Subtraction = 26,
     StridedSlice = 27,
-    Gather = 28
+    Gather = 28,
+    Mean = 29
 }
 
 // Base layer table to be used as part of other layers
@@ -349,6 +350,16 @@
     dataLayout:DataLayout = NCHW;
 }
 
+table MeanLayer {
+    base:LayerBase;
+    descriptor:MeanDescriptor;
+}
+
+table MeanDescriptor {
+    axis:[uint];
+    keepDims:bool = false;
+}
+
 table PadLayer {
     base:LayerBase;
     descriptor:PadDescriptor;
@@ -433,7 +444,8 @@
     ResizeBilinearLayer,
     SubtractionLayer,
     StridedSliceLayer,
-    GatherLayer
+    GatherLayer,
+    MeanLayer
 }
 
 table AnyLayer {