Add log for debug

This CL use flag to decide which log should be show on.
This flag can be dynamic turn on when use below command:
adb shell setprop log.tag."your tag" VERBOSE

Bug: 155121301
Test: manually test
Change-Id: I0f3a28c11f6bd055efc84feb41d646b6c033f5b7

src/com/android/settings/bluetooth/AdvancedBluetoothDetailsHeaderController.java

@@ -63,6 +63,7 @@ public class AdvancedBluetoothDetailsHeaderController extends BasePreferenceCont
         LifecycleObserver, OnStart, OnStop, OnDestroy, CachedBluetoothDevice.Callback {
     private static final String TAG = "AdvancedBtHeaderCtrl";
     private static final int LOW_BATTERY_LEVEL = 15;
+    private static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
 
     @VisibleForTesting
     LayoutPreference mLayoutPreference;
@@ -215,6 +216,11 @@ public class AdvancedBluetoothDetailsHeaderController extends BasePreferenceCont
 
         final int batteryLevel = BluetoothUtils.getIntMetaData(bluetoothDevice, batteryMetaKey);
         final boolean charging = BluetoothUtils.getBooleanMetaData(bluetoothDevice, chargeMetaKey);
+        if (DBG) {
+            Log.d(TAG, "updateSubLayout() icon : " + iconMetaKey + ", battery : " + batteryMetaKey
+                    + ", charge : " + chargeMetaKey + ", batteryLevel : " + batteryLevel
+                    + ", charging : " + charging + ", iconUri : " + iconUri);
+        }
         if (batteryLevel != BluetoothUtils.META_INT_ERROR) {
             linearLayout.setVisibility(View.VISIBLE);
             final TextView textView = linearLayout.findViewById(R.id.bt_battery_summary);
@@ -268,6 +274,9 @@ public class AdvancedBluetoothDetailsHeaderController extends BasePreferenceCont
         final BluetoothDevice bluetoothDevice = mCachedDevice.getDevice();
         final String iconUri = BluetoothUtils.getStringMetaData(bluetoothDevice,
                 BluetoothDevice.METADATA_MAIN_ICON);
+        if (DBG) {
+            Log.d(TAG, "updateDisconnectLayout() iconUri : " + iconUri);
+        }
         if (iconUri != null) {
             final ImageView imageView = linearLayout.findViewById(R.id.header_icon);
             updateIcon(imageView, iconUri);