message: Add option to delegate configuration proto/flatbuffer for fallback for any delegate.
diff: @@ -107,8 +107,10 @@ message NNAPISettings {
  // case.
  optional int32 no_of_nnapi_instances_to_cache = 5;
  + // Deprecated; use the fallback_settings in TFLiteSettings.
  + //
  // Whether to automatically fall back to TFLite CPU path.
  - optional FallbackSettings fallback_settings = 6;
  + optional FallbackSettings fallback_settings = 6 [deprecated = true];
  // Whether to allow use of NNAPI CPU (nnapi-reference accelerator) on Android
  // 10+ when an accelerator name is not specified. The NNAPI CPU typically
  @@ -238,6 +240,9 @@ message TFLiteSettings {
  // For configuring the EdgeTpuDelegate.
  optional EdgeTpuSettings edgetpu_settings = 8;
  +
  + // Whether to automatically fall back to TFLite CPU path.
  + optional FallbackSettings fallback_settings = 9;
  }
  // Whether to automatically fallback to TFLite CPU path on delegation errors.
  