Settings strings cleanup per standards.

Bugs: 5165745, 5163232, 5162668, 5162667, 5162328
Implementation of language and spelling changes requested by Design
such as WiFi. Also removed some dialog titles per Design. Will
file separate bug to have the titles removed properly; for now I
just made the string empty.

Change-Id: I56b251a0d639f8d25f0908c636226e0d6e7da6a5

More changes to add <xliff:g/> around raw HTML per Eric Fischer.

Fixed redundant <string> tag caught in review.