Merge "Support adding custom tags to APIs." am: 841022227d am: 5349732bf4 am: 571321c458 am: bc01819b67

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1469444

Change-Id: I0c06eaf7b29f555456cf4e75f7d68b0869fb9417