android: settings: Add reactive flushing as a default-disabled setting.

src/android/app/src/main/res/values/strings.xml

@@ -169,6 +169,8 @@
     <string name="renderer_force_max_clock_description">Forces the GPU to run at the maximum possible clocks (thermal constraints will still be applied).</string>
     <string name="renderer_asynchronous_shaders">Use asynchronous shaders</string>
     <string name="renderer_asynchronous_shaders_description">Compiles shaders asynchronously, reducing stutter but may introduce glitches.</string>
+    <string name="renderer_reactive_flushing">Use reactive flushing</string>
+    <string name="renderer_reactive_flushing_description">Improves rendering accuracy in some games at the cost of performance.</string>
     <string name="renderer_debug">Graphics debugging</string>
     <string name="renderer_debug_description">Sets the graphics API to a slow debugging mode.</string>
     <string name="use_disk_shader_cache">Disk shader cache</string>