Add Icons content observer to additional Launcher URI

Flag: EXEMPT BUGFIX
Bug: 445809851
Test: manually verified, see bug
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:32c3eafe14dafc17aef0f961f59d83b259316b42
Merged-In: I847021a776f4fe76f26429840a5c4259eddfbab6
Change-Id: I847021a776f4fe76f26429840a5c4259eddfbab6