I am re-posting this question because I found nothing from other previous answers asked by others.
All are saying "Uninstall previous app and Install new".
But What I want is:   I am upgrading my app Version, While I am installing it to device from android Studio Its showing Above error [INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES]. 
So, My Question is, How to Install new upgraded app over my old app without Uninstalling.
