Do not restrict app bounds by parent if overridden bounds exist

This removed the app bounds intersection added in 7566d76c.

It is outdated since insetsDecoupledConfiguration is enabled.
The appBounds from display no longer considers decor insets.
The test testAppBounds_RootConfigurationBounds will always fail
if the display info has cutout.

It may also compute inconsistent info in configuration, e.g.
override bounds=300x600, parent app bounds=600x300,
then the intersected app bounds is 300x300
 > If app calls Display#getSize, it will get the square bounds.
But mTmpStableBounds is still calculated from full bounds 300x600.
 > If app gets Configuration#screenWidthDp/screenHeightDp,
   it will get a portrait size.

The real case may happen on flexible split screen that one side
is shifted outside the screen. It's app bounds should be able to
put at a negative position.

For legacy apps that needs the app bounds excluding decor insets,
now it is done by ConfigurationContainer#applySizeOverrideIfNeeded.

Bug: 426114417
Flag: EXEMPT bugfix
Test: TaskTests#testComputeConfigResourceOverrides
Change-Id: I06c540226c676bdc600976ac004fd5121b654b65