New Pipeline: Fix some feature flagging

* Calling addKeyguardNotificationSuppressor was supposed to be only when the old pipeline was enabled, but it was still being used on the new pipeline, so I've guarded the calls.  This makes it easier to remove the old pipeline cleanly.

Test: manual
Bug: 218105118
Change-Id: I681dfeaf6ca352f3feb287064581b746e130c701
6 files changed