Align drop PREBUILT to internal am: 5a31d6337f

Original change: https://android-review.googlesource.com/c/platform/tools/tradefederation/prebuilts/+/1511436

Change-Id: I85f78fc96baed76f88504c12455ef71314073091
tree: de8c3652d65fe86512768815082fb39d97f394ad
  1. filegroups/
  2. test_harness/
  3. OWNERS