android: Don't log error when checking weak ref
android: Don't log error when checking weak ref

The point of a weak reference is to be able to try and deref it
even when the object is no longer around, so this is not an error.

Review URL: https://codereview.chromium.org/1489703002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#362485}

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