Fix crash that occurs on termination of the Godot engine on Android

[m4gr3d]

This PR + #85955 should address the last of the crashes visible in the logs when the Godot engine is destroyed on Android.

09:30:58.768 libc                     A  FORTIFY: pthread_mutex_destroy called on a destroyed mutex (0xb4000078f6a41bc4)
09:30:58.768 libc                     A  Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 13049 (GLThread 524), pid 13006 (e.editor.v4.dev)
09:30:59.018 DEBUG                    A  Cmdline: org.godotengine.editor.v4.dev
09:30:59.018 DEBUG                    A  pid: 13006, tid: 13049, name: GLThread 524  >>> org.godotengine.editor.v4.dev <<<
09:30:59.018 DEBUG                    A        #04 pc 00000000000c339c  /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/lib/arm64/libc++_shared.so (std::__ndk1::mutex::~mutex()+12) (BuildId: d7ce478d849eba1d3e692ae740f6c04a08fb8fab)
09:30:59.018 DEBUG                    A        #05 pc 00000000046c70f4  /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/lib/arm64/libgodot_android.so (MutexImpl<std::__ndk1::mutex>::~MutexImpl()+20)
09:30:59.018 DEBUG                    A        #06 pc 00000000082d8a9c  /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/lib/arm64/libgodot_android.so (Object::~Object()+1252)
09:30:59.018 DEBUG                    A        #07 pc 0000000002f952f4  /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/lib/arm64/libgodot_android.so (void memdelete<JavaClassWrapper>(JavaClassWrapper*)+44)
09:30:59.018 DEBUG                    A        #08 pc 0000000002f92b6c  /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/lib/arm64/libgodot_android.so (_terminate(_JNIEnv*, bool)+84)
09:30:59.018 DEBUG                    A        #09 pc 0000000002f92b08  /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/lib/arm64/libgodot_android.so (Java_org_godotengine_godot_GodotLib_ondestroy+32)
09:30:59.018 DEBUG                    A        #15 pc 0000000000004ef4  [anon:dalvik-classes12.dex extracted in memory from /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/base.apk!classes12.dex] (org.godotengine.godot.gl.GodotRenderer.onRenderThreadExiting+0)
09:30:59.018 DEBUG                    A        #24 pc 0000000000003c94  [anon:dalvik-classes12.dex extracted in memory from /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/base.apk!classes12.dex] (org.godotengine.godot.gl.GLSurfaceView$GLThread.guardedRun+0)
09:30:59.018 DEBUG                    A        #29 pc 00000000000045a8  [anon:dalvik-classes12.dex extracted in memory from /data/app/~~Ec9iAIQ5fzLqEPPNImdlBQ==/org.godotengine.editor.v4.dev-SqKR3gzRh7N7i790JSQ_Zg==/base.apk!classes12.dex] (org.godotengine.godot.gl.GLSurfaceView$GLThread.run+0)

Those crashes have been ongoing for some time but were made more visible by #94661.

[akien-mga]

Thanks!