VisualInterruptionDecisionProvider: suppress peek/pulse when app suspended

If an app is suspended in focus mode, we should suppress peek and pulse;
otherwise, the notifications may *immediately* peek or pulse when focus
mode ends.

Modify the new BubbleAppSuspendedSuppressor to suppress interruptions
from suspended apps for peek, pulse, and bubble; and rename/rearrange
code as necessary.

Note that, despite touching code in the visual interruptions refactor,
this change is *not* related to or flagged by the refactor's feature
flag; this is a long-standing omission in our interruption logic, not a
bug in the refactored code.

Bug: 329620290
Flag: NA
Test: atest VisualInterruptionDecisionProviderImplTest
Change-Id: I0437f1a286183a28689b7ef0c8a604a7bc0398b6