Handle incomplete protectors in destroyAllWeakTokenBasedProtectors() am: 397f5416a1 am: 1375406ce5

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2775373

Change-Id: Ica6528613b894aec40848ae22b5c3fbde4266dfe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>