Update 1.5.4.91

Improvements and bug fixes.

Changes:

The aircraft control setting "Constant Turn Mode" has been added.
A bug that could cause the game to freeze on some devices has been fixed.
A bug that could cause the sound to not stop when minimizing the game has been fixed.
A bug that caused decals on aircraft to be fuzzy at the beginning of a battle has been fixed.
A bug that caused the speed of an aircraft to be set to 0 when appearing in a battle has been fixed.
The incorrect function of free view camera in aircraft mode has been fixed.