[AndroidSms] Add metrics for FcmConnectionEstablisher

This CL adds metrics to FcmConnectionEstablisher class to track retries
and failures. See go/awm-cros-fcm for details.

Bug: 926314
Change-Id: I6089fbb5e44a8b2c69fd20b787214378014ed216
Reviewed-on: https://chromium-review.googlesource.com/c/1443896
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Jeremy Klein <jlklein@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Azeem Arshad <azeemarshad@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#628049}(cherry picked from commit 3edbb0ea725d7b4cfc3871dc3a5fd00bcfd62a9b)
Reviewed-on: https://chromium-review.googlesource.com/c/1450742
Cr-Commit-Position: refs/branch-heads/3683@{#140}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
5 files changed