[RESTRICT AUTOMERGE] Log to EventLog on prepareUserStorage failure am: 2f2e7d84f8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17452585

Change-Id: Ibb1049aa4c143ba2d4e04a021cb2546519a1996e
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>