[player] Resets shift key of keyboard after pressing a key

Exceptions
- BACKSPACE, RETURN, SPACE (like iPad)

projects/player/modules/key-input/components/keyboard/keyboard.component.ts

@@ -54,6 +54,7 @@ export class KeyboardComponent {
       }
       default: {
         this.keyClicked.emit(this.shift ? key[1] : key[0]);
+        this.shift = false;
       }
     }
   }