Merge "Fill in javadocs for translation feature." into sc-dev am: 1553fc7f...

Merge "Fill in javadocs for translation feature." into sc-dev am: 1553fc7f am: 44ef8355 am: c6caf136

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15597859

Change-Id: If47d2f678466ccf67feed85d21f15090d5608d56