ART: Revert change to LiveRange::Dump

Changes back the LiveRange printing format to "[start,end)" for better
clarity. However, it removes the space after comma due to b/1189305
and prints the "ranges" attribute with curly brackets to improve
readability.

This is a resubmission of CL Ic83025fa78d6f1edb5e0e39d66160182b0198ab8
which fixes a compilation issue on target.

Bug: 21189305
Change-Id: Ic232c02ba19a710ead67793a039f99c0345353c7