Revert "Cancel notification if media title is invalid"

This reverts commit 381f6d61.

Reason for revert: This change caused b/278354453 and potentially other  unintended stability issues for 1P partners. The originating team has proposed alternative solutions without the negative impacts in https://b.corp.google.com/issues/274775190#comment23 and DevRel will review the proposal for the next steps.

Change-Id: I28846b7d775be9d724fad4d9a4414b5781ffb951