shortcut-customization: add jelly colors flag

Flag for controlling jelly colors in the Shortcut Customization App
when jelly-colors is enabled.

- Add flag to ash_features, flag_descriptions, and about_flags.
- Update enum to include new flag.

Bug: b:275718921
Test: unit_tests --gtest_filter=AboutFlagsHistogramTest.*:AboutFlagsTest.*
Test: Manually enabled and disabled flag using UI.
Change-Id: I7b9c29fa42e93c7feb15dcf919bb0d5cb00d8d7a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4396753
Commit-Queue: Ashley Prasad <[email protected]>
Reviewed-by: Michael Checo <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1126215}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 15c6ba7..c29bdef4 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -6162,6 +6162,12 @@
     "Enable the diagnostic page in Shimless RMA for showing detailed device "
     "information";
 
+const char kShortcutCustomizationJellyName[] =
+    "Enable jelly colors for the Shortcut Customization App";
+const char kShortcutCustomizationJellyDescription[] =
+    "Enable jelly colors for the Shortcut Customization App. Requires "
+    "jelly-colors flag to be enabled.";
+
 const char kSchedulerConfigurationName[] = "Scheduler Configuration";
 const char kSchedulerConfigurationDescription[] =
     "Instructs the OS to use a specific scheduler configuration setting.";