Merge "Enable improved user separation by default." am: 9ad4f042ff am: 66aedd52a2

Original change: https://android-review.googlesource.com/c/platform/system/vold/+/1522938

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I2c7d8951108250458b19bac6a35ef3517cebdcc4