Disable flaky ModelDownloader integration tests. am: 5247b140e9

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libtextclassifier/+/23472318

Change-Id: I6d0d73f9fa537a2bbf4d9729089bca1349d49de7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>