Use "echo + append" rather than "sed -i" in flatbuffers bzl.
Use "echo + append" rather than "sed -i" in flatbuffers bzl.

PiperOrigin-RevId: 341342637

tensorflow/tflite-support,tensorflow/tflite-support,tensorflow/tflite-support,tensorflow/tflite-support,tensorflow/tflite-support,tensorflow/tflite-support