* added instruction text property in file pciker to make user unable to provide custom instructions
* Added default instruction text
* made the changes to make sure existing app do not crashes because of instructionText prop
* Solve issue - existing file pickers wont display anything if we don't default to the default instruction text
* changes in operation.json file
* migration script for adding instructionText prop
* removed unwanted operations.json file
Co-authored-by: Kavin Venkatachalam <kavin.saratha@gmail.com>