Use art::GetAndroidRoot instead of ANDROID_HOST_OUT in art::CommonArtTestImpl.

Do not use the environment variable ANDROID_HOST_OUT to find the
Android Root in art::CommonArtTestImpl; rely on art::GetAndroidRoot
instead.

Test: m test-art-host-gtest
Change-Id: I89fc9288164b57bc3f6542864cece312b6df2fd1
1 file changed