[declutter] Adjust IPH triggering to be less aggressive

Pinpoint has identified a regression caused by enabling declutter iph
by default. When digging into it, I noticed that the iph feature
was misconfigured to trigger any number of times during a session.
While in the code, also adding more guardrails to ensure the
regression is fixed/landed smoothly, although it may be overkill.

Bug: 397992504
Change-Id: Ic70825d58f56f40f96b49422b4858cec968c5597
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6344334
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Commit-Queue: Brandon Wylie <wylieb@google.com>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1431279}