WifiLogger: speed up compression

Some rough benchmarking suggests that using
BEST_COMPRESSION may cause us to take 4 seconds
to service a dump() request. The same benchmarking
indicates that using BEST_SPEED will be about
10x as fast, and yield output that's only 5%
larger.

Switch to BEST_SPEED, to avoid slowing down
bug report generation.

BUG=28986501
TEST=manual

Manual test:
- Enable Wi-Fi Verbose Logging
$ adb bugreport foo.zip
- verify that foo.zip contains base-64 encoded
  ringbuffer dumps

Change-Id: I0eac83def5cf393a6babdd481079086ea11a5a96
(cherry picked from commit 9a312a13ba34712f3de7f4d0c8d04ff695a41cae)
1 file changed
tree: 83f8af8e125a62cf8e4e47c68557cbe82be72b4e
  1. service/
  2. tests/