Skip load app name from PackageManager while init the BatteryEntry.

- getApplicationLabel is time-consuming.
[Before]
https://pprof.corp.google.com/?id=bade2601da25f6169b0685a3e2a3e5cc
https://screenshot.googleplex.com/86R5DhMgcyQakys
[After]
https://pprof.corp.google.com/?id=2ccb1e88222e96db1fbcc072470a254c
https://screenshot.googleplex.com/7QviDFSpgzoQcg6

Bug: 349120408
Fix: 349120408
Test: atest + pprof
Flag: EXEMPT bug fix
Change-Id: I1eed60cea9c5bd3f77f38993f7d04906aa811da5

src/com/android/settings/fuelgauge/batteryusage/BatteryEntry.java

@@ -22,7 +22,6 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.IPackageManager;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
-import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.UserInfo;
 import android.graphics.drawable.Drawable;
 import android.os.BatteryConsumer;
@@ -176,18 +175,7 @@ public class BatteryEntry {
                 }
             }
             if (mDefaultPackageName != null) {
-                PackageManager pm = context.getPackageManager();
-                try {
-                    ApplicationInfo appInfo =
-                            pm.getApplicationInfo(mDefaultPackageName, 0 /* no flags */);
-                    mName = pm.getApplicationLabel(appInfo).toString();
-                } catch (NameNotFoundException e) {
-                    Log.d(
-                            TAG,
-                            "PackageManager failed to retrieve ApplicationInfo for: "
-                                    + mDefaultPackageName);
-                    mName = mDefaultPackageName;
-                }
+                mName = mDefaultPackageName;
             }
             mTimeInForegroundMs =
                     uidBatteryConsumer.getTimeInProcessStateMs(