Merge changes from topic "snapuserd-enable-read-ahead" am: 362b2b75 am:...

Merge changes from topic "snapuserd-enable-read-ahead" am: 362b2b75 am: aa5be17a am: 646db6c4 am: 27595361

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1690661

Change-Id: I0cb4f91ab117bb6c61d0764ddf8d95e70a564f57