Disable -Wunused-value for surfaceflinger am: 95fd424

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/30468223

Change-Id: I99a1c77d94f063c8a7fd8b90ab61fcb9e258a2cd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

Author: appujee