CCA: Expose getState and waitStateChange to Tast

Expose state-related functions to Tast side. getState and
waitStateChange are corresponded to getState and observeStateChange in
cca_ui.js in Tast repo.

Bug: b:242800694
Test: tast run $DUT camera.CCAUIRecordVideo camera.CCAUIExpert
Change-Id: Ib8859340e1dee318dc90118c3d3b509c527a998d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4522664


Reviewed-by: Chu-Hsuan Yang <chuhsuan@chromium.org>
Commit-Queue: Kam Kwankajornkiet <kamchonlathorn@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1143945}