Improve strings.

Change-Id: I8d23479cac769ec5f6b3ae6dde9faa17cb6df025
contacts: don't assume the device has an sdcard

Change-Id: Ie9025a803a3df1ee2ab364c1c073880d89186f01
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
contacts: return the first sdcard entry found

Change-Id: I8b036da9c04ae6b7c78d75163134a4ca816dc79b
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>