crash-reporter: remove gflags dependency We are switching to using chromeos/flag_helper.h instead to standardize the code everywhere. BUG=chromium:402631 TEST=`FEATURES=test emerge-panther crash-reporter` TEST=`test_that -b panther <ip> e:logging_.*` Change-Id: I62b911a54f89d853235d0540460cbea119f66e9e Reviewed-on: https://chromium-review.googlesource.com/212140 Reviewed-by: Mike Frysinger <[email protected]> Tested-by: Steve Fung <[email protected]> Commit-Queue: Steve Fung <[email protected]>