Merge "Add maxTargetSdk restriction to unused APIs." am: 6bcd335c6a am: d1dda8ac48 am: a30f3e0b34 am: 6dceba437c

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

Change-Id: I0ace32ac2192705b5662c21cfef97dabc4a18f77