Add `const`-ed `context()` accessor to `tflite::Subgraph`
Add `const`-ed `context()` accessor to `tflite::Subgraph`

PiperOrigin-RevId: 407136596
Change-Id: I6b7e9ccdd83718cd126bffd9a3e260ce46568f1d

Intel-Corporation/tensorflow,yongtang/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_tf_optimizer,yongtang/tensorflow,Intel-tensorflow/tensorflow,yongtang/tensorflow,gautam1858/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,paolodedios/tensorflow,tensorflow/tensorflow,Intel-Corporation/tensorflow,paolodedios/tensorflow,Intel-Corporation/tensorflow,tensorflow/tensorflow,Intel-Corporation/tensorflow,paolodedios/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-pywrap_saved_model,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow,gautam1858/tensorflow,gautam1858/tensorflow,yongtang/tensorflow,karllessard/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,yongtang/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,gautam1858/tensorflow,paolodedios/tensorflow,yongtang/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-experimental_link_static_libraries_once,gautam1858/tensorflow,paolodedios/tensorflow,tensorflow/tensorflow-pywrap_saved_model,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,gautam1858/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow,paolodedios/tensorflow,Intel-Corporation/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow,karllessard/tensorflow,yongtang/tensorflow,paolodedios/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow-experimental_link_static_libraries_once,karllessard/tensorflow,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-pywrap_saved_model,karllessard/tensorflow,gautam1858/tensorflow,Intel-Corporation/tensorflow,Intel-tensorflow/tensorflow,karllessard/tensorflow,tensorflow/tensorflow-experimental_link_static_libraries_once,paolodedios/tensorflow,karllessard/tensorflow,gautam1858/tensorflow,yongtang/tensorflow,Intel-tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_tf_optimizer,tensorflow/tensorflow-experimental_link_static_libraries_once,tensorflow/tensorflow,tensorflow/tensorflow-pywrap_saved_model,Intel-Corporation/tensorflow,tensorflow/tensorflow-pywrap_saved_model,gautam1858/tensorflow,tensorflow/tensorflow-pywrap_saved_model,tensorflow/tensorflow-pywrap_tf_optimizer,yongtang/tensorflow,gautam1858/tensorflow,paolodedios/tensorflow,karllessard/tensorflow,yongtang/tensorflow,tensorflow/tensorflow-pywrap_tf_optimizer,paolodedios/tensorflow