Merge "Add flag for widgets in Launcher preview" into sc-v2-dev am: 0058f293eb am: 53d761f63c

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14940360

Change-Id: I4dc90b358c0c31e2c2c4ece7b00f5c3921573cd1