Use 180 degree as general upside down for rotation choice

The "UpsideDown" field of DisplayRotation stands for reverse portrait.
So the general up side down rotation should be ROTATION_180.

Otherwise a landscape display will get 90 as invalid and 180 as valid.

Portrait display (default h>w)
  mLandscapeRotation=ROTATION_90 mSeascapeRotation=ROTATION_270
  mPortraitRotation=ROTATION_0 mUpsideDownRotation=ROTATION_180

Landscape display (default w>h)
  mLandscapeRotation=ROTATION_0 mSeascapeRotation=ROTATION_180
  mPortraitRotation=ROTATION_270 mUpsideDownRotation=ROTATION_90

Bug: 204197290
Test: adb shell wm size 2000x1000
      Disable auto-rotation.
      Rotate the device 90-degree counterclockwise.
      The rotation hint button should show.
Change-Id: Iea6ae5d9ac1ffdf7333f7cc52e644f10ed5311a8