Settings: Port "Development shortcut" (1/2)

New setting under "Debug settings" that enables the development shortcut
Change-Id: I9a43e611911f2e278605715f714860ad11236fd9

Modify the Development shortcut help text
Change-Id: Iaa6d87f5044a46e8c0f8d88a4fc9bf9a494188b8

Change-Id: I9a43e611911f2e278605715f714860ad11236fd9
Remove activity tags with fragments from Manifest

Change-Id: I95118ebe7b876cf29ee0bfdfe876ebd839619b89

Conflicts:
	AndroidManifest.xml
Improve notification tone string

Change-Id: I731903a7bcda38229502de33dbc83c44e3782996