Remove -Wall from cflags. am: 5b448cde8f am: c09b1b6214 am: 52ccad761b

Original change: https://android-review.googlesource.com/c/platform/system/libziparchive/+/2794926

Change-Id: I543383d1f37cb3ba7ae109f31ae83f9e2615996b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>