Query storage size instead of calculate size of installed APP

From android S, Storage Settings show files of images/videos/audios
category instead of installed APP of each category. So it's
necessary to change the way to calculate size information.

This change also
- StorageItemPreference shows changing storage size units instead
  of fixed GB. It helps UX for categories of only small size files.
- Query media provider for size of Documents and others.
- Query media provider for size of Trash.

Bug: 170918505
Bug: 177892478
Bug: 179871408
Bug: 184379946
Bug: 186077224
Bug: 187128447
Test: atest com.android.settings.deviceinfo
      atest com.android.settings.deviceinfo.storage
      make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.deviceinfo
      make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.deviceinfo.storage
      manual visual
      Click each file category to count files size is the same as
      displayed in Storage Settings.
Change-Id: I37c7b3a4b5860323cb55581b23a90f583f4af216

src/com/android/settings/deviceinfo/StorageItemPreference.java

@@ -17,7 +17,8 @@
 package com.android.settings.deviceinfo;
 
 import android.content.Context;
-import android.content.res.Resources;
+import android.text.TextUtils;
+import android.text.format.Formatter;
 import android.util.AttributeSet;
 import android.widget.ProgressBar;
 
@@ -25,7 +26,6 @@ import androidx.preference.Preference;
 import androidx.preference.PreferenceViewHolder;
 
 import com.android.settings.R;
-import com.android.settings.utils.FileSizeFormatter;
 
 public class StorageItemPreference extends Preference {
     public int userHandle;
@@ -49,12 +49,8 @@ public class StorageItemPreference extends Preference {
 
     public void setStorageSize(long size, long total) {
         mStorageSize = size;
-        setSummary(
-                FileSizeFormatter.formatFileSize(
-                        getContext(),
-                        size,
-                        getGigabyteSuffix(getContext().getResources()),
-                        FileSizeFormatter.GIGABYTE_IN_BYTES));
+        setSummary(getStorageSummary(size));
+
         if (total == 0) {
             mProgressPercent = 0;
         } else {
@@ -82,7 +78,10 @@ public class StorageItemPreference extends Preference {
         super.onBindViewHolder(view);
     }
 
-    private static int getGigabyteSuffix(Resources res) {
-        return res.getIdentifier("gigabyteShort", "string", "android");
+    private String getStorageSummary(long bytes) {
+        final Formatter.BytesResult result = Formatter.formatBytes(getContext().getResources(),
+                bytes, Formatter.FLAG_SHORTER);
+        return TextUtils.expandTemplate(getContext().getText(R.string.storage_size_large),
+                result.value, result.units).toString();
     }
 }