Add secure setting for Global Actions Panel debug mode.

Changes grid-based power menu logic to use new debug setting.

Bug: 123397865
Bug: 127644235

Test: Automated tests pass. Manual testing turning off/on debug setting.
Change-Id: Ic95188bd10a433f5c58f0f37a098a872e65d8150
diff --git a/core/tests/coretests/src/android/provider/SettingsBackupTest.java b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
index 9fa04ef..fda37c8 100644
--- a/core/tests/coretests/src/android/provider/SettingsBackupTest.java
+++ b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
@@ -637,6 +637,7 @@
                  Settings.Secure.ENABLED_NOTIFICATION_POLICY_ACCESS_PACKAGES,
                  Settings.Secure.ENABLED_PRINT_SERVICES,
                  Settings.Secure.GLOBAL_ACTIONS_PANEL_AVAILABLE,
+                 Settings.Secure.GLOBAL_ACTIONS_PANEL_DEBUG_ENABLED,
                  Settings.Secure.IMMERSIVE_MODE_CONFIRMATIONS,
                  Settings.Secure.INCALL_BACK_BUTTON_BEHAVIOR,
                  Settings.Secure.INPUT_METHOD_SELECTOR_VISIBILITY,