Link Speed Metrics Proto

Add a histogram of link speed values with count and rssi values.

Collect this metrics only when enabled in settings. By default, we don't
collect this metrics.

Bug: 78354985
Test: Settings Unittest
Change-Id: I683dfb45a01de5e1243d612a117a5544b0d4dc05
diff --git a/core/tests/coretests/src/android/provider/SettingsBackupTest.java b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
index 676d8d9..c22dd13 100644
--- a/core/tests/coretests/src/android/provider/SettingsBackupTest.java
+++ b/core/tests/coretests/src/android/provider/SettingsBackupTest.java
@@ -471,6 +471,7 @@
                     Settings.Global.WIFI_FREQUENCY_BAND,
                     Settings.Global.WIFI_IDLE_MS,
                     Settings.Global.WIFI_IS_UNUSABLE_EVENT_METRICS_ENABLED,
+                    Settings.Global.WIFI_LINK_SPEED_METRICS_ENABLED,
                     Settings.Global.WIFI_MAX_DHCP_RETRY_COUNT,
                     Settings.Global.WIFI_MOBILE_DATA_TRANSITION_WAKELOCK_TIMEOUT_MS,
                     Settings.Global.WIFI_NETWORK_SHOW_RSSI,