Fixing wrong window insets estimation

Launcher was estimating the landscape insets incorrectly
causing the UI to get reloaded if device is rotated. This also
caused widgets to be refetched as a result of grid size change

Bug: 218067434
Test: Verified locally that the window bounds do not change
Change-Id: Ia7228296c78ea3056f4859e43696d4bfd9522d3c