Migrate test/mlts/benchmark to androidx.test

See go/jetpack-test-android-migration

Test: make checkbuild
Change-Id: I69a40ad308d04a17df58f3123936339db988ec65
Merged-In: I69a40ad308d04a17df58f3123936339db988ec65
(cherry picked from commit 8ff11fa3e61b2b7a1195bacc29d6bbea27b5fcbd)
6 files changed