Add knobs for tweaking blocking helper thresholds

Added both blocking helper parameters to Global Settings to allow for
tweaking stats/values. Added listeners for value updates (so that
channels are updated properly with new thresholds).

Bug: 77143005
Test: manually, test cases
Change-Id: Ia5cfb29ca40500a694261bd5e9e60fa1f34e742a
diff --git a/core/tests/coretests/src/android/provider/SettingsBackupTest.java b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
index dafd475..e9e6cb6 100644
--- a/core/tests/coretests/src/android/provider/SettingsBackupTest.java
+++ b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
@@ -131,6 +131,8 @@
                     Settings.Global.BLE_SCAN_LOW_LATENCY_WINDOW_MS,
                     Settings.Global.BLE_SCAN_LOW_LATENCY_INTERVAL_MS,
                     Settings.Global.BLE_SCAN_BACKGROUND_MODE,
+                    Settings.Global.BLOCKING_HELPER_DISMISS_TO_VIEW_RATIO_LIMIT,
+                    Settings.Global.BLOCKING_HELPER_STREAK_LIMIT,
                     Settings.Global.BLUETOOTH_A2DP_SINK_PRIORITY_PREFIX,
                     Settings.Global.BLUETOOTH_A2DP_SRC_PRIORITY_PREFIX,
                     Settings.Global.BLUETOOTH_A2DP_SUPPORTS_OPTIONAL_CODECS_PREFIX,