Update on "[executorch][serialization] Move DataSegment into shared common.fbs"

So that `DataSegment` can be shared by incoming data.fbs.

Differential Revision: [D65434369](https://our.internmc.facebook.com/intern/diff/D65434369/)

[ghstack-poisoned]

Author: lucylq

exir/common_schema.py

@@ -9,9 +9,9 @@
 from dataclasses import dataclass
 from enum import IntEnum
 
-
 # Check exir/common.fbs for explanations of these fields.
 
+
 class ScalarType(IntEnum):
     BYTE = 0
     CHAR = 1

exir/schema.py

@@ -12,7 +12,7 @@
 
 from executorch.exir.backend.compile_spec_schema import CompileSpec
 
-from executorch.exir.common_schema import ScalarType, DataSegment
+from executorch.exir.common_schema import DataSegment, ScalarType
 
 
 @dataclass