Merge "Add HIDDEN_API_POLICY to @TestApi.i" am: c6b54a3a9c am: ab5ea0c1c5 am: 4c1da9c0df

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1460404

Change-Id: Ie90f87cde805b09f3aba24c61b5b457038cb067d