SlidingDrawer deprecated
does this mean I should import the code into my project to be sure that it will be supported in the future?
Personally, I would dump SlidingDrawer and do something else for all new app development.
That being said, SlidingDrawer should be in the Android SDK for the foreseeable future. As the docs note, Google is not supporting it any more, which means, potentially, sometime, it may no longer work at all and will have to be dropped. If you are still using it at that time, then you will have a decision to make. For example, AbsoluteLayout was deprecated in late 2008 IIRC, and it is still available for use.
There is nothing stopping you from trying to fork SlidingDrawer to make one in a library project, though you will need to copy some resources and make code changes to point to your resources rather than ones internal to the framework.
To reiterate @MarioLenci's comment, there is a library that implements it: https://github.com/umano/AndroidSlidingUpPanel