I had the same issue (4.13.2). Since we are a PC project, I turned off the compilation options for Android and other platforms (Edit->Project Settings->SupportedPlatforms) and the thread appears to have gone away.
Note that I couldn’t find much if any CPU time actually being spent in that thread. As near as I can tell the profiler is listing for how long the indivdual threads are active, not how much CPU they are consuming. This means that threads in “Wait” mode clutter up the profiler quite a bit as they are theoretically active but in process sleeping until woken by interruption.
I believe that the Android detector starts on game start and ends on game end and therefore is quite likely to head this list since it is active for so long. Good news if your PC ever transforms itself into a Android mid-game! I suspect that somehow in detecting an android it is looking for some aspect like a thread that might not exist strictly at gamestart time but will appear very slightly later, and since the thread never appears it sits and waits, so it is probably somewhat less silly/performant than it appears.
A side note relative to all this - there is a lot more likelihood of the issue in the above .jpg being in the GameThread than in the threads above it (many of which when I have been profiling recently often appear to be in Wait mode).
I’m far from an expert on this aspect of UE however. YMMV.