It's been the case for a long time that questions about installing and using the development tools for Android - adb, fastboot, the emulator - and the infrastructure behind installing and updating them - the SDK manager - are on-topic on this site. The rationale for this is that often, these tools are used for non-development purposes. Power users might use adb for changing settings on the device, for controlling it from a PC, or for backups. They might use the emulator to investigate an app without installing it, or to use an app their device doesn't support. And of course fastboot is often used for installing custom ROMs, or for upgrading Android by hand if an OTA upgrade is not available.
That said, I've seen a lot of flags and close-votes recently asking for questions of this type to be closed as development questions. Does this represent a change in the views of the community? Should we start treating these questions as off-topic?
I'm keen to hear lots of people's views about this, to form a consensus.