[Settings] Performance tuning for intent ACTION_ENHANCED_4G_LTE_CHANGED

Adjust the ordering of accessing to avoid the rule checks
isVoLteProvisioned() when not required.

Bug: 140542283
Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=Enhanced4gLteSliceHelperTest
Change-Id: I8604a27d211895a6b33e0f6d0d78f5772912ee01

src/com/android/settings/network/telephony/Enhanced4gLteSliceHelper.java

@@ -163,20 +163,31 @@ public class Enhanced4gLteSliceHelper {
      * @param intent action performed
      */
     public void handleEnhanced4gLteChanged(Intent intent) {
-        final int subId = getDefaultVoiceSubId();
+        // skip checking when no toggle state update contained within Intent
+        final boolean newValue = intent.getBooleanExtra(EXTRA_TOGGLE_STATE, false);
+        if (newValue != intent.getBooleanExtra(EXTRA_TOGGLE_STATE, true)) {
+            notifyEnhanced4gLteUpdate();
+            return;
+        }
+
+        final int subId = getDefaultVoiceSubId();
+        if (!SubscriptionManager.isValidSubscriptionId(subId)) {
+            notifyEnhanced4gLteUpdate();
+            return;
+        }
 
-        if (SubscriptionManager.isValidSubscriptionId(subId)) {
         final VolteQueryImsState queryState = queryImsState(subId);
-            if (queryState.isVoLteProvisioned()) {
         final boolean currentValue = queryState.isEnabledByUser()
                 && queryState.isAllowUserControl();
-                final boolean newValue = intent.getBooleanExtra(EXTRA_TOGGLE_STATE,
+        if (newValue == currentValue) {
-                        currentValue);
+            notifyEnhanced4gLteUpdate();
-                if (newValue != currentValue) {
+            return;
+        }
+
+        // isVoLteProvisioned() is the last item to check since it might block the main thread
+        if (queryState.isVoLteProvisioned()) {
             setEnhanced4gLteModeSetting(subId, newValue);
         }
-            }
-        }
         notifyEnhanced4gLteUpdate();
     }