Merge "Fix LruCache, allow std:string caching" am: 1477714262 am: 614857c782

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2627034

Change-Id: I77397bc5467bd33b2b52492169f47199c0bad582
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>