Scale the preview content from full preview size to match the container size

Screenshot:
  - Full preview: https://screenshot.googleplex.com/ngtQivW5PcM.png
  - Small preview: https://screenshot.googleplex.com/sEy6UMQnJ7M.png
Video: https://drive.google.com/file/d/1S4ng6NlBN19VGHQSLCVL1_28NR7UvX6k/view?usp=sharing
Known issue in the video: the text size will change per selected theme, and then push down the bottom components, will fix later.

Test: Manually
Bug: 146475648
Bug: 151286773
Change-Id: I9063efa9ee2418f2b76c2d17a2e539a5e4acbe8b