Remove unnecessary override of TDA#setWindowingMode

Since I526620a182e1915628bf381454dd9247a8c3639f removed
mDisplayWindowingMode, it becomes the same as super.setWindowingMode.

Bug: 163976519
Flag: EXEMPT remove outdated code
Test: DisplayWindowSettingsTests
Change-Id: Ideb94673f7399dbc3969758b4c50da8c41f6159c

1 file changed