Fix build warning due to WebSettings now being abstract
Fix build warning due to WebSettings now being abstract

WebSettings was made abstract in
https://android-git.corp.google.com/g/#/c/177360

current.txt was updated, but this causes a build warning because 16.txt was not
updated to match.

Change-Id: I4e00297361048509fab236f292c07d8a0df28f28

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base