Merge "libbinder(_ndk): document getService" am: 36937323b0 am: 4d50c47b44 am: a0e5b96b6e

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2016418

Change-Id: I1d6d61ef7ad8a4d2145134fa4587e07ed93fc15a