Merge "template updates to support constraint layout reference"

          elif:reference ?>/reference<?cs

          elif:downloads ?>/downloads<?cs /if ?><?cs

        else ?><?cs

          if:(guide||develop||training||reference||tools||sdk||samples) ?><?cs

          if:reference.testSupport ?>/reference/android/support/test<?cs

          elif:reference.wearableSupport ?>/reference/android/support/wearable<?cs

          elif:reference.constraintSupport ?>/reference/android/support/constraint<?cs

          elif:(guide||develop||training||reference||tools||sdk||samples) ?><?cs

            if:guide ?>/guide<?cs

            elif:training ?>/training<?cs

            elif:reference ?>/reference<?cs

          elif:wearpreview ?>/wear/preview<?cs

          elif:work ?>/work<?cs

          elif:design ?>/design<?cs

          elif:reference.testSupport ?>/reference/android/support/test<?cs

          elif:reference.wearableSupport ?>/reference/android/support/wearable<?cs

          elif:walkthru ?>/walkthru<?cs /if ?><?cs

        /if ?>/_book.yaml" /><?cs

        /if ?>