Move all headers under executorch dir. (#2707)

Summary:
bypass-github-export-checks

Reviewed By: kimishpatel

Differential Revision: D55409522

Author: shoumikhin

build/build_apple_frameworks.sh

@@ -151,7 +151,8 @@ mkdir -p "$HEADERS_PATH"
   //extension/module: \
 | rsync -av --files-from=- "$SOURCE_ROOT_DIR" "$HEADERS_PATH/executorch"
 
-cp "$SOURCE_ROOT_DIR/extension/apple/ExecuTorch/Exported/"{*.h,*.modulemap} "$HEADERS_PATH"
+cp "$SOURCE_ROOT_DIR/extension/apple/ExecuTorch/Exported/"*.h "$HEADERS_PATH/executorch"
+cp "$SOURCE_ROOT_DIR/extension/apple/ExecuTorch/Exported/"*.modulemap "$HEADERS_PATH"
 
 echo "Creating frameworks"
 

extension/apple/ExecuTorch/Exported/module.modulemap

@@ -1,5 +1,5 @@
 module ExecuTorch {
-  umbrella header "ExecuTorch.h"
+  umbrella header "ExecuTorch/ExecuTorch.h"
 
   export *
 }