v0.8.2: Various bugfixes:

- Added a safety check to AndroidGame
- fixed Burning not checking if a thieve's item is null
- fixed wand of regrowth overriding tall grass and placing grass where it shouldn't
- fixed unique potions being vulnerable to explosions
- fixed tengu placing traps over plants
- fixed items not being IDed in rankings if players dies with an ankh

android/src/main/java/com/shatteredpixel/shatteredpixeldungeon/android/AndroidGame.java

@@ -107,7 +107,12 @@ public class AndroidGame extends AndroidApplication {
 		view = (GLSurfaceView)graphics.getView();
 		
 	}
-	
+
+	@Override
+	public void onBackPressed() {
+		//do nothing, game should catch all back presses
+	}
+
 	@Override
 	public void onWindowFocusChanged(boolean hasFocus) {
 		super.onWindowFocusChanged(hasFocus);