SurfaceComposerClient: add a range check in setAlpha am: f4bd36b72d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/22434167

Change-Id: I6ab336bed33a26b1bb9fc855ffe43ed1b0ceadc5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>