Android: enable support for volume button events

- Enable events KEY_VOLUMEUP and KEY_VOLUMEDOWN on Android.

- Adds a project setting to override volume buttons. It would disable system volume changes when the buttons are used within the project.

platform/android/java/editor/src/main/java/org/godotengine/editor/BaseGodotEditor.kt

@@ -258,12 +258,14 @@ abstract class BaseGodotEditor : GodotActivity(), GameMenuFragment.GameMenuListe
 		super.onGodotSetupCompleted()
 		val longPressEnabled = enableLongPressGestures()
 		val panScaleEnabled = enablePanAndScaleGestures()
+		val overrideVolumeButtonsEnabled = overrideVolumeButtons()
 
 		runOnUiThread {
 			// Enable long press, panning and scaling gestures
 			godotFragment?.godot?.renderView?.inputHandler?.apply {
 				enableLongPress(longPressEnabled)
 				enablePanningAndScalingGestures(panScaleEnabled)
+				setOverrideVolumeButtons(overrideVolumeButtonsEnabled)
 			}
 		}
 	}
@@ -482,6 +484,8 @@ abstract class BaseGodotEditor : GodotActivity(), GameMenuFragment.GameMenuListe
 	 */
 	protected open fun overrideOrientationRequest() = true
 
+	protected open fun overrideVolumeButtons() = false
+
 	/**
 	 * Enable long press gestures for the Godot Android editor.
 	 */

platform/android/java/editor/src/main/java/org/godotengine/editor/BaseGodotGame.kt

@@ -46,6 +46,8 @@ abstract class BaseGodotGame: GodotEditor() {
 		private val TAG = BaseGodotGame::class.java.simpleName
 	}
 
+	override fun overrideVolumeButtons() = java.lang.Boolean.parseBoolean(GodotLib.getGlobal("input_devices/pointing/android/override_volume_buttons"))
+
 	override fun enableLongPressGestures() = java.lang.Boolean.parseBoolean(GodotLib.getGlobal("input_devices/pointing/android/enable_long_press_as_right_click"))
 
 	override fun enablePanAndScaleGestures() = java.lang.Boolean.parseBoolean(GodotLib.getGlobal("input_devices/pointing/android/enable_pan_and_scale_gestures"))