Improve wallpaper preview loading transition
- Fix WallpaperPreviewBitmapTransformation rounding error when scaling
- Precompute the thumbnail background color to use as placeholder if
possible
- Allow the placeholder to be serialized in WallpaperInfo so it's
available when opening the preview
- If available, obtain a low res preview as bitmap
- Remove unused views from wallpaper_preview_card
- Make TouchForwardingLayout transparent from loading to avoid it
showing in the fragment transition
Before/after videos: https://drive.google.com/drive/folders/1-PqL0BCOuet9pnrYVphewpwAcvVoBCwo?usp=sharing
Bug: 184111918
Test: visual check
Change-Id: Icaabafd5c430a0324899e471aa8f28453ab04f1a
30 files changed