Fix flakey test: CallRedirectionServiceTest#testServiceUnbindOnNullBinding am: e543dd9d75

Original change: https://googleplex-android-review.googlesource.com/c/platform/cts/+/22309275

Change-Id: I6d2e134dd766f17a58c9e0bdb8bb2d30fe19ce65
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>