Do not set the excluded layers on task snapshot...

...if the layer has already been released. This fixes a race condition
where the layer can be released on another thread.

Bug: 448401959
Flag: EXEMPT BUGFIX
Test: presubmit
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:30eac09d41055becf888106e5020b71adf2e1e53
Merged-In: Iee0b572116f243439958e7ccf3d4edd90b4fa627
Change-Id: Iee0b572116f243439958e7ccf3d4edd90b4fa627