Use std::thread in input code

This will allow us to get away from the Thread.h class of libutils, thus
preventing the priority from getting set explicitly.

This, in turn, will ensure that SetTaskProfiles call does not provide
conflicting information.

Bug: 378761104
Test: presubmit
Flag: EXEMPT refactor
Change-Id: Id7674339ed52f9488236673667778abcc5bb4c3d