Show Arrow education tip on WidgetsBottomSheet. This tip is shown only
once either in widgets full sheet or bottom sheet.
Test: Tested manually
Bug: 185354491
Change-Id: I6d770ed0906a5cb0f5bcfe6ae0cd327b790cf164
Test: Launch widgets bottom sheet, search popup to confirm the expected
background color is applied.
Bug: 183601302
Change-Id: I300a364605e00a0d8046a907a40f4cb797ec161e
1. Show widget previews in their expected cell sizes.
2. Update the bottom picker to use a table layout rather than
a horizontal scrollbar.
3. Move the title and cell size description to the bottom of
the preview.
Test: Run AddConfigWidgetTest
Manually open full and bottom widgets picker and observe
widget previews.
Video: https://drive.google.com/file/d/1K8A8hK5B4FgPTsX3cb-Yt4a_VjI0pk-w/view?usp=sharing
Bug: 179797520
Change-Id: I938612cb2e2477ce4a3a2d6c8891a0a36fc0978c
