Merge "Renamed getTimeStamp to getTimestampMillis and added docs." am: 6f1b7122f3 am: d8935b34f4 am: 50ccf0437f am: 063a4aa8dd

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1869978

Change-Id: Icd2a198893c78bcc6c5991afaca4c733489f6712