Use ICU JNI wrappers for phonebook labels

Switch from using native code registered as sqlite callbacks to using
JNI wrappers for accessing ICU AlphabeticIndex. Stop using specialized
sort keys for Simplified Chinese because ICU code can correctly label
the characters directly.

Bug:
Change-Id: I0568b3a406495c147c7b9b3e72835d11d93f9d16
6 files changed