[automerged blank] Add FrameDropper_test to mts 2p: 2f18164f1f

Blank merge reason: Change-Id I9b41fc700cf76c6a6a789b5beabe4f93dd82ce8b with SHA-1 6921ca6085 is in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/13618505

Change-Id: Ibb565ea0fa234793ba51a338010f27300303a1fa