Generate WallpaperPicker2 ktfmt inclusion file

The CL updates the ktfmt_includes.txt file used by
WallpaperPicker2. Starting from this CL, all new Kotlin files will
be checked using ktfmt.

The ktfmt_includes.txt file is generated by the following steps:
$ cd $ANDROID_BUILD_TOP/packages/apps/WallpaperPicker2
$ $ANDROID_BUILD_TOP/external/ktfmt/generate_includes_file.py --output=ktfmt_includes.txt src/ tests/ src_override/

Bug: 235461679
Test: Manual
Change-Id: I2ad42f73e258dfcf4b9f3bb302279945ab57f3c8
diff --git a/ktfmt_includes.txt b/ktfmt_includes.txt
new file mode 100644
index 0000000..37bbd6a
--- /dev/null
+++ b/ktfmt_includes.txt
@@ -0,0 +1,9 @@
++src/
++src_override/
++tests/
+-src/com/android/wallpaper/model/WallpaperColorsViewModel.kt
+-src/com/android/wallpaper/model/WorkspaceViewModel.kt
+-src/com/android/wallpaper/module/LargeScreenMultiPanesChecker.kt
+-src/com/android/wallpaper/module/MultiPanesChecker.kt
+-src/com/android/wallpaper/util/DisplayUtils.kt
+-src/com/android/wallpaper/widget/GridRowSpacerDecoration.kt