Install ADB And Fastboot Android Tools In Ubuntu Via PPA

A package called "android-tools", which comes with "adb" and "fastboot" command line utilities, has been uploaded to the Ubuntu 12.10 Quantal Quetzal repositories recently. I've got a request to upload this package in a PPA for older Ubuntu releases, so I've backported it to Ubuntu 12.04, 11.10 and 11.04.