Google Drive Setup!

*** New Features and Details ***
* Set up two threads for background tasks: one for data polling, one for Google Drive uploads
* Added an activity class (no UI) for connecting to Drive and creating/managing an iResponsible folder with data
* Tapping the button to start the service now displays Google account picker
* On successful sign in (including accepting Drive Access permission) the service sets up the two threads with the timed tasks
* Data is currently stored in CSV format (which may or may not change upon further testing)
* Currently nonfunctional Google Sign In button (to be removed), ended up preferring integrating the sign in into the same button tap

*** To be implemented very soon ***
* Erase cache data upon successful upload
* Avoid repetitive creation of same file/folder on Drive