Merge "Expose ApnSetting#TYPE_*_STRING constants" am: bff8389872 am: 04e788bebd

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1610923

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I519807c3b0ac093ffa6fec23cc07b48fb9ef1d36