Android: minimum size for IME, so that it takes focus

In API 28, 0 width views can't take focus, so if someone tries to position the IME without setting a width, they'll stop getting text events.

Tested on Android 9: with a 0 size, it would send correctly letters a, b, c, etc. but not numbers.

android-project/app/src/main/java/org/libsdl/app/SDLActivity.java

@@ -1029,6 +1029,14 @@ public class SDLActivity extends Activity implements View.OnSystemUiVisibilityCh
             this.y = y;
             this.w = w;
             this.h = h;
+
+            /* Minimum size of 1 pixel, so it takes focus. */
+            if (this.w <= 0) {
+                this.w = 1;
+            }
+            if (this.h + HEIGHT_PADDING <= 0) {
+                this.h = 1 - HEIGHT_PADDING;
+            }
         }
 
         @Override