Messaging: Further code improvements

* Remove redundant casts
* getParcelable(ArrayList|Exra) without class argument is deprecated
* ViewPager.setOnPageChangeListener -> addOnPageChangeListener
* RecyclerView.setOnScrollListener -> addOnScrollListener
* Remove unused initializations
* Remove unused code

Change-Id: I21beb6c90c675a4f2cfd7e3d5ebbd18b745f5911

src/com/android/messaging/sms/BugleApnSettingsLoader.java

@@ -466,7 +466,7 @@ public class BugleApnSettingsLoader implements ApnSettingsLoader {
         LogUtil.i(LogUtil.BUGLE_TAG, "Loading APNs from local APN table");
         final SQLiteDatabase database = ApnDatabase.getApnDatabase().getWritableDatabase();
         final String mccMnc = PhoneUtils.getMccMncString(PhoneUtils.getDefault().getMccMnc());
-        Cursor cursor = null;
+        Cursor cursor;
         cursor = queryLocalDatabase(database, mccMnc, apnName);
         if (cursor == null) {
             cursor = queryLocalDatabase(database, mccMnc, null/*apnName*/);
@@ -513,7 +513,7 @@ public class BugleApnSettingsLoader implements ApnSettingsLoader {
             selection = SELECTION_NUMERIC + " AND " + SELECTION_APN;
             selectionArgs = new String[] { numeric, apnName };
         }
-        Cursor cursor = null;
+        Cursor cursor;
         try {
             cursor = db.query(ApnDatabase.APN_TABLE, APN_PROJECTION_LOCAL, selection, selectionArgs,
                     null/*groupBy*/, null/*having*/, ORDER_BY, null/*limit*/);

src/com/android/messaging/sms/DatabaseMessages.java

@@ -476,7 +476,7 @@ public class DatabaseMessages {
             mParts = new ArrayList<>();
             mPartsProcessed = false;
             for (int i = 0; i < nParts; i++) {
-                mParts.add((MmsPart) in.readParcelable(getClass().getClassLoader()));
+                mParts.add(in.readParcelable(getClass().getClassLoader()));
             }
         }
 

src/com/android/messaging/sms/MmsUtils.java

@@ -1544,7 +1544,7 @@ public class MmsUtils {
 
     public static int bugleStatusForMms(final boolean isOutgoing, final boolean isNotification,
             final int messageBox) {
-        int bugleStatus = MessageData.BUGLE_STATUS_UNKNOWN;
+        int bugleStatus;
         // For a message we sync either
         if (isOutgoing) {
             if (messageBox == Mms.MESSAGE_BOX_OUTBOX || messageBox == Mms.MESSAGE_BOX_FAILED) {