Ignore UnbundledChooserActivityTest am: 78c6881968

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/IntentResolver/+/18614358

Change-Id: Id31d4e49ac1fa3ed52651be5d7bc0b28a3a7867d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>