Disables display content scaling for foldables

When setting folded area with changes both in width and height (set
0,0,540,1080 to a 1080x2160 device), the content of display will be
auto-scaled to physical display size. It is not an expected behavior
for foldable devices. Disable auto-scale to fix this issue.

1. LogicalDisplay.configureDisplayLocked() scales the contents according
the DisplayInfo.flags.
2. DisplayInfo.flags should not be overridden by design for a logical
display.
3. Adds disableDisplayScaling() for DisplayFoldController to bypass that.

Bug: 123245311
Test: atest WmTests
Test: adb shell wm folded-area 0,0,840,1260
Change-Id: I9a24c5d56799981b4f2cfe82fdf1898d87193681