Adding MetricsEvent for "Mobile network" UI.

Adding ENUMS of MetricsEvent for "Mobile network" UI. It will
record events of any button clicked, switch toggled and value
changed inside "Mobile network".

Bug: 34775714
Test: Manual
Change-Id: I98f81489319f6cda6921b88eb04e79978cad800d
Merged-In: I98f81489319f6cda6921b88eb04e79978cad800d
diff --git a/src/com/android/phone/CdmaOptions.java b/src/com/android/phone/CdmaOptions.java
index 8749565..7c09265 100644
--- a/src/com/android/phone/CdmaOptions.java
+++ b/src/com/android/phone/CdmaOptions.java
@@ -26,6 +26,8 @@
 import android.telephony.CarrierConfigManager;
 import android.text.TextUtils;
 
+import com.android.internal.logging.MetricsLogger;
+import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.internal.telephony.Phone;
 
 /**
@@ -95,6 +97,8 @@
                     new Preference.OnPreferenceClickListener() {
                         @Override
                         public boolean onPreferenceClick(Preference preference) {
+                            MetricsLogger.action(mButtonAPNExpand.getContext(),
+                                    MetricsEvent.ACTION_MOBILE_NETWORK_APN_SETTINGS);
                             // We need to build the Intent by hand as the Preference Framework
                             // does not allow to add an Intent with some extras into a Preference
                             // XML file