Merge "Document the limitation to a hundred callbacks." am: 665d54db52

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1313813

Change-Id: Id2f70609c46ec6252b7e734c1e5838016314400f
tree: 867948e9eaa8c6c861a583910011b1cb33a7c395
  1. core/
  2. services/
  3. tests/