Android: logical plugin names should trim "lib" prefix on android #551

If you run osvr_print_tree on android with a running server (standalone at least, not tested with auto-start), the logical plugin names in the tree have a "lib" prefix, whereas they do not on PC. This makes cross-platform configuration impossible as aliases will need to be different on PC vs Android.

The logical plugin names in the tree should have the "lib" prefix trimmed, so that they match the corresponding names on the PC.