Document that native file dialog is only available on Android 10+ devices.

Author: syntaxerror247

doc/classes/DisplayServer.xml

@@ -782,7 +782,7 @@
 				Displays OS native dialog for selecting files or directories in the file system.
 				Each filter string in the [param filters] array should be formatted like this: [code]*.png,*.jpg,*.jpeg;Image Files;image/png,image/jpeg[/code]. The description text of the filter is optional and can be omitted. It is recommended to set both file extension and MIME type. See also [member FileDialog.filters].
 				Callbacks have the following arguments: [code]status: bool, selected_paths: PackedStringArray, selected_filter_index: int[/code]. [b]On Android,[/b] the third callback argument ([code]selected_filter_index[/code]) is always [code]0[/code].
-				[b]Note:[/b] This method is implemented if the display server has the [constant FEATURE_NATIVE_DIALOG_FILE] feature. Supported platforms include Linux (X11/Wayland), Windows, macOS, and Android.
+				[b]Note:[/b] This method is implemented if the display server has the [constant FEATURE_NATIVE_DIALOG_FILE] feature. Supported platforms include Linux (X11/Wayland), Windows, macOS, and Android (API level 29+).
 				[b]Note:[/b] [param current_directory] might be ignored.
 				[b]Note:[/b] Embedded file dialog and Windows file dialog support only file extensions, while Android, Linux, and macOS file dialogs also support MIME types.
 				[b]Note:[/b] On Android and Linux, [param show_hidden] is ignored.

doc/classes/FileDialog.xml

@@ -205,7 +205,7 @@
 		<member name="title" type="String" setter="set_title" getter="get_title" overrides="Window" default="&quot;Save a File&quot;" />
 		<member name="use_native_dialog" type="bool" setter="set_use_native_dialog" getter="get_use_native_dialog" default="false">
 			If [code]true[/code], and if supported by the current [DisplayServer], OS native dialog will be used instead of custom one.
-			[b]Note:[/b] On Android, it is only supported when using [constant ACCESS_FILESYSTEM]. For access mode [constant ACCESS_RESOURCES] and [constant ACCESS_USERDATA], the system will fall back to custom FileDialog.
+			[b]Note:[/b] On Android, it is only supported for Android 10+ devices and when using [constant ACCESS_FILESYSTEM]. For access mode [constant ACCESS_RESOURCES] and [constant ACCESS_USERDATA], the system will fall back to custom FileDialog.
 			[b]Note:[/b] On Linux and macOS, sandboxed apps always use native dialogs to access the host file system.
 			[b]Note:[/b] On macOS, sandboxed apps will save security-scoped bookmarks to retain access to the opened folders across multiple sessions. Use [method OS.get_granted_permissions] to get a list of saved bookmarks.
 			[b]Note:[/b] Native dialogs are isolated from the base process, file dialog properties can't be modified once the dialog is shown.

platform/android/display_server_android.cpp

@@ -63,6 +63,11 @@ bool DisplayServerAndroid::has_feature(Feature p_feature) const {
 			return (native_menu && native_menu->has_feature(NativeMenu::FEATURE_GLOBAL_MENU));
 		} break;
 #endif
+		case FEATURE_NATIVE_DIALOG_FILE: {
+			String sdk_version = OS::get_singleton()->get_version().get_slicec('.', 0);
+			return sdk_version.to_int() >= 29;
+		} break;
+
 		case FEATURE_CURSOR_SHAPE:
 		//case FEATURE_CUSTOM_CURSOR_SHAPE:
 		//case FEATURE_HIDPI:
@@ -72,7 +77,6 @@ bool DisplayServerAndroid::has_feature(Feature p_feature) const {
 		//case FEATURE_MOUSE_WARP:
 		case FEATURE_NATIVE_DIALOG:
 		case FEATURE_NATIVE_DIALOG_INPUT:
-		case FEATURE_NATIVE_DIALOG_FILE:
 		//case FEATURE_NATIVE_DIALOG_FILE_EXTRA:
 		case FEATURE_NATIVE_DIALOG_FILE_MIME:
 		//case FEATURE_NATIVE_ICON: