[PS] Update icon background for PS, Widget and web.

PS:
https://screenshot.googleplex.com/3xVtx5bPD296pUd
https://screenshot.googleplex.com/B3MkSoyfkBJPRsA
https://screenshot.googleplex.com/8pqs2ZsNatEvcBF
https://screenshot.googleplex.com/9CK9hqHSGfc6jin

Widget:
https://screenshot.googleplex.com/AdcmB7ScDnxK2Hv
https://screenshot.googleplex.com/9XkaghiVrx3YBLq
https://screenshot.googleplex.com/7hh3xU4JTUXG4X5
https://screenshot.googleplex.com/Ao2wWAAGVF4kHpe

Bug: 320562455
Test: manual
Flag: aconfig com.google.android.apps.nexuslauncher.enable_inject_private_space_tile teamfood
Change-Id: I46d9ae92cc21a4ba6e66be2271c584ee0e3514cd