fix(tablet): fix magnification banner in dark mode am: 44660662 am: 05723287 am: bbdcb350

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/21466797



Change-Id: I527db51e653055b7935cb89b08312ac66d8a86fd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>