Welcome tour smooth launch

Remove the loader mechanism and instead have the activity
determine if the tour is required.

Also a minor refactoring of moving the VOICE_SEARCH_REQUEST_CODE from
MaterialSearchViewController into AbstractActivityController.

Bug: 16124942 "WarmWelcome screen is shown after Inbox view is presented..."
Change-Id: Icd0ed2a976d8e8acc387336d1a81c690ab961efb
4 files changed