Refactor IWindow#insetsControlChanged to use InsetsSourceControl.Array

InsetsSourceControl can be sent to client process through server push,
or client pull (IWindowSession#relayout).

We need to make sure they are sync'ed. Refactor to use the Array object
instead of raw array, so that we can add additional seqId to it later.

Bug: 339380439
Test: refactor only
Change-Id: Id765867794812a344ddf0f9292edf90b814f598a