Handle incomplete protectors in destroyAllWeakTokenBasedProtectors() am: 397f5416a1 am: 1375406ce5 am: 81ae939e46

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

Change-Id: I933a2ce779ea382087375b54ca5e814f7d4125a1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>