Add a shell command to execute an app function

Note that shell already have the permission execute_app_function.

Test: adb shell cmd app_function execute-app-function --package <pkg name> --function  com.example.android.architecture.blueprints.todoapp#NoteFunctions_createNote --parameters '{"createNoteParams":{"title":\"My title\"}}'

Fixes: 406576149

Flag: EXEMPT shell cmd only update

Change-Id: Ifeff7741a058f8435f3f5e8932f2e070fdd834d5