logd: Allow (some) headers to be individually importable

LogReader.h needs to be individually importable.

Fix a few others, drop includes of local includes, let them be
included in source instead and allow headers to be included
alphabetically. Was not a complete audit since goal was to
separate LogReader.h out from the pack.

Bug: 27242723
Change-Id: Ic7759ef90995e5bd285810706af33550c73cf5b5