Plumb the animation info from convertToTranslucent to transition

convertToTranslucent is currently its own sort-of startActivity.
Because it doesn't go through normal startActivity flow, the
activity-options used for it's transition weren't being plumbed
into the transition system. This adds that for the only current
use-case (shared-element transitions).

Bug: 283213473
Test: Open messages, search, click back out of search.
Change-Id: I12befccffc198ab73ef8038527c0dea416a6f3ca