Remove star import

Author: daymxn

firebase-common/src/main/java/com/google/firebase/heartbeatinfo/HeartBeatInfoStorage.java

@@ -18,8 +18,9 @@
 import android.os.Build;
 import androidx.annotation.RestrictTo;
 import androidx.annotation.VisibleForTesting;
-import androidx.datastore.preferences.core.*;
+import androidx.datastore.preferences.core.MutablePreferences;
 import androidx.datastore.preferences.core.Preferences;
+import androidx.datastore.preferences.core.PreferencesKeys;
 import com.google.firebase.datastorage.JavaDataStorage;
 import com.google.firebase.datastorage.JavaDataStorageKt;
 import java.text.SimpleDateFormat;