Quickly exit VtsHalNeuralnetworks*TargetTest on failure

This change adds the AndroidTest.xml flag --gtest_break_on_failure to
cause the gtest to terminate after an error has been reached. This early
termination is important in the case where an NN HAL service crashes
mid-test, and all remaining tests would otherwise continue to run.

Bug: 197035200
Test: m vts -j
Test: vts-tradefed
Change-Id: I0b9a14345475e432b93f92c23010a8b39712443a