Fix overview animation after reboot.

Tasks have their start bounds set to fullscreen by wm core upon reboot.
To prevent tasks from jumping from start bounds to end bounds, set start
bounds equal to end bounds.

Bug: 365496442
Test: Manual
Flag: com.android.window.flags.enable_desktop_windowing_persistence
Change-Id: I916ab4cfd76d8caa27b23afa42926c2bfc22133e