ART: Change hash table load factors in images to 0.6.

Use 0.6 for both interned strings and class table. This
provides a better trade-off between performance and memory
use than the previous value 0.7.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 175869411
Bug: 243310398
Change-Id: Ica7eaf21714dffc4c54c850cd8129e99a7dff648
1 file changed