ART: Add simple failure list to tail of testrunner output

After repeating the output of failed tests, print the sorted list
of failed test configurations. The list is separated from the full
output by a separator line.

Bug: 37116837
Test: m test-art-host
Test: manually fail test
Change-Id: I2a206fba47db2626d390bb60c70b843f56a1b987