Merge "Allow app zygote preload to retain files across fork" am: f334f4ed...

Merge "Allow app zygote preload to retain files across fork" am: f334f4ed am: 5465af84 am: cdc831ba am: 9a44a29d

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1739393

Change-Id: Ib37b6cbbc111fc0a268bf0bfb5fa4d1cb0d8c1c9