Merge changes from topic "am-37170c8f22554766afc25915c7a99d41" into tm-qpr-dev-plus-aosp

* changes:
  Merge changes from topic "nscobie-hwui_unit_tests" am: 463a0128 am: 1b66b6a5
  Enable hwui_unit_tests in presubmit for libs/hwui am: ff0bf7b1 am: c80b1c67
  Fix GraphicsStats#findRootPath and disable CacheManager#trimMemory tests am: 24921a03 am: 600da2e0
  Change hwui_unit_tests (and benchmarks) to push to non-root writable dir am: 1aa54918 am: 85e8dbe6