Settings: Add a setting to toggle wifi scan throttling

Scan throttling affects apps which are used by testers for survey-like
application. Add a hidden setting which can be toggled via adb commands
to turn off all scan throttling.

Bug: 111763749
Test: Unit tests
Test: `adb shell settings put global wifi_scan_throttle_enabled 0` on
user build.
Change-Id: I6c9a468c573239914b88de0afcdd7e477429cb16
diff --git a/core/tests/coretests/src/android/provider/SettingsBackupTest.java b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
index 37dec13..c18b128 100644
--- a/core/tests/coretests/src/android/provider/SettingsBackupTest.java
+++ b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
@@ -488,6 +488,7 @@
                     Settings.Global.WIFI_SAVED_STATE,
                     Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE,
                     Settings.Global.WIFI_SCAN_INTERVAL_WHEN_P2P_CONNECTED_MS,
+                    Settings.Global.WIFI_SCAN_THROTTLE_ENABLED,
                     Settings.Global.WIFI_SCORE_PARAMS,
                     Settings.Global.WIFI_SLEEP_POLICY,
                     Settings.Global.WIFI_SUPPLICANT_SCAN_INTERVAL_MS,