Dialog disappears on device rotation

[reverse-unina]

When i perform these sequences of events, the dialog on screen disappears:

Sequence 1-3:

1. Open Side Drawer
2. Click on Settings
3. Click on:
   a. Left Ruler
   b. Right Ruler
   c. Angle Measure
4. Orientation Change

[Yonjuni]

I guess we should just temporary lock the rotation to portrait.

[Yonjuni]

Closed #5