CCA: remove suspendObserver which outlives portrait mode

`addOnetimeObserver()` wraps the inside the function so
`removeObserver()` cannot find the same observer. Also because
suspendObserver is not called every time, it should be a normal
observer.

BUG=b:332473422
Test=Manually by console log

Change-Id: I329d1ea831dab5ed47abc620df5b265fe4e3bb0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5420050
Commit-Queue: Dorah Kim <dorahkim@google.com>
Reviewed-by: Sean Li <seannli@google.com>
Cr-Commit-Position: refs/heads/main@{#1284253}