Change insets property from wm to debug.

persist.wm is not editable on user builds, changing it to debug so it is
editable. Making the change so its flippable on dp1.

Bug: 111084606
Test: atest CtsInputMethodTestCases
      Manually verified adb shell setprop persist.debug.* is editable on
      user build.
Change-Id: I693abad22d2b087f0df6ac5c138ba942252cc620