message: TFLM: Update Average pool with correct version.
  Apart from float support (version 1), we also have int8 support for AVG POOL 2D, which is version 2.
diff: @@ -30,7 +30,7 @@ AllOpsResolver::AllOpsResolver() {
  AddBuiltin(BuiltinOperator_CONCATENATION, Register_CONCATENATION(), 1, 3);
  AddBuiltin(BuiltinOperator_DEPTHWISE_CONV_2D, Register_DEPTHWISE_CONV_2D(), 1,
  3);
  - AddBuiltin(BuiltinOperator_AVERAGE_POOL_2D, Register_AVERAGE_POOL_2D());
  + AddBuiltin(BuiltinOperator_AVERAGE_POOL_2D, Register_AVERAGE_POOL_2D(), 1, 2);
  AddBuiltin(BuiltinOperator_ABS, Register_ABS());
  AddBuiltin(BuiltinOperator_SIN, Register_SIN());
  AddBuiltin(BuiltinOperator_COS, Register_COS());
  