[DO NOT MERGE] Change the LPNH flag to read from server flag "ENABLE_LONG_PRESS_NAV_HANDLE_MPR". am: 75183ceed5

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/25303662

Change-Id: I9ef5d303c1c0ed30a02e56e039699de44307201c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>