Migrate away from deprecated Truth APIs. am: 041b499d83 am: f3eb6ad182 am: 666e2f6c28

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/localepicker/+/1437940

Change-Id: I4f5f0d8deb98e264ad8e021ebfbc9d39a2c03e9e