GitLab

* Deprecate PhoneHub.InitialConnecting as it is no longer needed, but
  was not corrected when moving metrics from ash to phonehub
* Fix PhoneHub.NotificationOptIn -> PhoneHub.NotificationOptInEvents
* Fix PhoneHub.Screen.OnSettingsButtonClicked ->
  honeHub.Screen.ScreenOnSettingsButtonClicked

Note that following metrics currently emit properly on ToT
(manually visible from chrome://histograms):

PhoneHub.InterstitialScreenEvent.BluetoothOrWifiDisabled
PhoneHub.InterstitialScreenEvent.Onboarding.ExistingMultideviceUser
PhoneHub.InterstitialScreenEvent.OnboardingDismissPrompt

Fixed: 1164584
Bug: 1106937
Change-Id: I977a3e454c9ed0add6e0efc669a45dc6349c5110
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2625277
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843329}