Updated Wi-Fi hotspot dialog to the Material Spec.

+ If there is scrolling then force the scrollbars to always appear.
+ Align contents of the dialog with the title.
+ Change "Network SSID" to "Network name".
+ Added wifi_* styles to other style xml files so that Wi-Fi hotspot dialogs are visible on tablets.
+ Move layout_width/height from res/layout/{wifi_dialog.xml, wifi_dialog_row.xml} from style into the xml file.

Bug: 17684359
Change-Id: I42fb69132d6ba0fb8d9853de6f5524f29e6b70b6