logcat: posixize and extend long arguments

(cherry pick from commit d85f6461b647d6f6e4c02d837884a0bda78930ba)

- change _ to - for long arguments
- added --tail as hidden undocumented alias for -t
- added --head as hidden undocumented alias for --max-count

Bug: 27706081
Change-Id: I614cc83ae56b305b267f64ed05dc3ed3027dabd4
1 file changed