[automerge] Fallback magnification mode settings if window magnification...

[automerge] Fallback magnification mode settings if window magnification feature is not supported 2p: bbbbc366 2p: 23912ba6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17352106

Bug: 213414385
Change-Id: Ie22e0951a44016a97504176ada1b8fd5c48dc644