IMS: Clean up Conference URI system property.

Remove system property "persist.dbg.ims_volte_enable".
Add platform configuration flag and user's enhanced 4G
LTE setting to decide IMS capability.

Change-Id: I1ee4dfb8e73ae7bf72a3daafef6957736a560606
CRs-Fixed: 727689
Dialer: truncate hint text for search box

There's not enough space on hdpi if voice search is enabled.
Showing truncated text is better than showing truncated 2 lines.

Before: http://imgur.com/aSUJm7X
After: http://imgur.com/LthsLsh

Change-Id: I2f140b2e61d575ea0c745bd95eb48b9950602316