Another default refresh Rate of physics engine

[MaxLuchs]

Hello,

with a higher higher refresh rate of the Godot physics engine the game runs a a lot smoother for me.
Maybe better to set the Engine's refresh rate to a higher value by default according to the screen refresh rate.

In the autoload-script:

`
func _refresh_settings():
log_info("_refresh_settings()");
set_display_refresh_rate(oculus_mobile_settings_cache["display_refresh_rate"]);
...
Engine.iterations_per_second = oculus_mobile_settings_cache["display_refresh_rate"] * 2
_need_settings_refresh = false;

var oculus_mobile_settings_cache = {
"display_refresh_rate" : 90,
"boundary_visible" : false,
"tracking_space" : ovrVrApiTypes.OvrTrackingSpace.VRAPI_TRACKING_SPACE_LOCAL_FLOOR,
"default_layer_color_scale" : Color(1.0, 1.0, 1.0, 1.0),
"extra_latency_mode" : ovrVrApiTypes.OvrExtraLatencyMode.VRAPI_EXTRA_LATENCY_MODE_ON,
"foveation_level" : FoveatedRenderingLevel.Off,
"foveation_dynamic" : 0,
"swap_interval" : 1,
"clock_levels_cpu" : 2,
"clock_levels_gpu" : 2,
}
`