BraveNewPipeLegacy: (Kitkat) fix getFreeStorageSpace()

use available methods on Kitkat to getFreeStorageSpace() or in
case of using SAF just assume there is enough space as the Os.fstatvfs()
is not available and there is no quick solution.

app/src/braveLegacy/java/org/schabi/newpipe/streams/io/BraveStoredDirectoryHelper.java

@@ -0,0 +1,60 @@
+package org.schabi.newpipe.streams.io;
+
+import android.os.Build;
+import android.os.StatFs;
+import android.system.ErrnoException;
+import android.system.Os;
+import android.system.StructStatVfs;
+
+import java.io.FileDescriptor;
+
+public final class BraveStoredDirectoryHelper {
+
+    private BraveStoredDirectoryHelper() {
+
+    }
+
+    public static BraveStructStatVfs statvfs(final String path) throws ErrnoException {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            final StructStatVfs stat = Os.statvfs(path);
+            return new BraveStructStatVfs(stat.f_bavail, stat.f_frsize);
+        } else {
+            final StatFs stat = new StatFs(path);
+            return new BraveStructStatVfs(stat.getAvailableBlocksLong(),
+                    stat.getBlockSizeLong()
+            );
+        }
+    }
+
+    public static BraveStructStatVfs fstatvfs(final FileDescriptor fd) throws ErrnoException {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            final StructStatVfs stat = Os.fstatvfs(fd);
+            return new BraveStructStatVfs(stat.f_bavail, stat.f_frsize);
+        } else {
+            // TODO find a real solution for KitKat to determine the free fs on FileDescriptor
+            // return just a fake value. '1' is just used to not exceed Long.MAX_VALUE as both
+            // values are multiplied by the caller
+            return new BraveStructStatVfs(Long.MAX_VALUE, 1);
+        }
+    }
+
+    public static class BraveStructStatVfs {
+        /**
+         * @noinspection checkstyle:MemberName
+         */
+        public final long f_bavail;
+        /**
+         * @noinspection checkstyle:MemberName
+         */
+        public final long f_frsize;
+
+        /**
+         * @noinspection checkstyle:ParameterName
+         */
+        BraveStructStatVfs(final long f_bavail,
+                           final long f_frsize) {
+            this.f_bavail = f_bavail;
+            this.f_frsize = f_frsize;
+        }
+    }
+}

app/src/braveLegacy/java/org/schabi/newpipe/streams/io/StoredDirectoryHelper.java

@@ -12,8 +12,6 @@
 import android.os.Build;
 import android.os.ParcelFileDescriptor;
 import android.provider.DocumentsContract;
-import android.system.Os;
-import android.system.StructStatVfs;
 import android.util.Log;
 
 import androidx.annotation.NonNull;
@@ -192,12 +190,12 @@ public boolean isDirect() {
      */
     public long getFreeStorageSpace() {
         try {
-            final StructStatVfs stat;
+            final BraveStoredDirectoryHelper.BraveStructStatVfs stat;
 
             if (ioTree != null) {
                 // non-SAF file, use statvfs with the path directly (also, `context` would be null
                 // for non-SAF files, so we wouldn't be able to call `getContentResolver` anyway)
-                stat = Os.statvfs(ioTree.toString());
+                stat = BraveStoredDirectoryHelper.statvfs(ioTree.toString());
 
             } else {
                 // SAF file, we can't get a path directly, so obtain a file descriptor first
@@ -208,7 +206,7 @@ public long getFreeStorageSpace() {
                         return Long.MAX_VALUE;
                     }
                     final FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
-                    stat = Os.fstatvfs(fileDescriptor);
+                    stat = BraveStoredDirectoryHelper.fstatvfs(fileDescriptor);
                 }
             }