This change also removes the usage of "fillBoth" keyWidth from 7-inch
tablet layouts.
Bug: 6480505
Change-Id: I9ed58e0b49138fa9e1610c2b008798eedb19dd26
* Remove keyXPos and keyWidth from key_*.xml and make it more generic.
* Add keyXPos and keyWidth to <include/> generalized key_*.xml.
* Remove zero width <Spacer/> and fold into successive <include/>.
Change-Id: I4b5c02a165ba0bc9ef8741be0b4938c1efaf5e27