Remove parameter throwOnError of windowForClientLocked

Only a few wallpaper methods (actionOnWallpaper) passes true.
Most callers pass false and check if the window is not found,
then do nothing.

This avoids the confusing log "Window Session Crash" when the
invocation is reached after the caller window was dead or removed.
The existing warning log "Failed looking up window" is enough.

Bug: 163976519
Flag: EXEMPT remove outdated code
Test: CtsWindowManagerDeviceWindow
Change-Id: I4f88d54f8561243bbfedf928b239bc7e1443c2bb