[automerger skipped] Merge "Make getExternalStorageMountMode as SystemApi" into sc-dev am: d158483a -s ours

am skip reason: skip tag Change-Id I51bc7bd3f355fadd9de56ac267469c2352eb0ffa with SHA-1 839aa852 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13671771

Change-Id: Ib7b762fcc33e3e29b3df348c3216e18a07ce6029