Merge "Add maxTargetSdk restriction to unused APIs." am: 6bcd335c6a am: d1dda8ac48 am: a30f3e0b34

Original change: https://android-review.googlesource.com/c/platform/external/libphonenumber/+/1467828

Change-Id: Ie6671b3058bea303ce0b2b8d7d68348e63b51086