Add MOUNT_FLAG_VISIBLE to visible stub volumes

The visibility setting of a removable device shared with Chrome OS is
passed via Disk flags. When a device (stub volume) is marked as visible,
we should set the MOUNT_FLAG_VISIBLE flag to it.

Bug: 123377807
Bug: 142684891
Bug: 132796154
Test: Toggle the visibility setting of a removable device in the Chrome
Test: OS Settings app > Confirm that the device is visible to Android
Test: apps only when it is marked as visible.
Test: Tested in R

Change-Id: I19289596345690b1802738122fe274eeb41f9361

core/java/android/os/storage/DiskInfo.java

@@ -50,6 +50,8 @@ public class DiskInfo implements Parcelable {
     public static final int FLAG_DEFAULT_PRIMARY = 1 << 1;
     public static final int FLAG_SD = 1 << 2;
     public static final int FLAG_USB = 1 << 3;
+    /** The FLAG_STUB_VISIBLE is set from vold, which gets the flag from outside (e.g., ChromeOS) */
+    public static final int FLAG_STUB_VISIBLE = 1 << 6;
 
     public final String id;
     @UnsupportedAppUsage
@@ -152,6 +154,10 @@ public class DiskInfo implements Parcelable {
         return (flags & FLAG_USB) != 0;
     }
 
+    public boolean isStubVisible() {
+        return (flags & FLAG_STUB_VISIBLE) != 0;
+    }
+
     @Override
     public String toString() {
         final CharArrayWriter writer = new CharArrayWriter();

services/core/java/com/android/server/StorageManagerService.java

@@ -1537,6 +1537,9 @@ class StorageManagerService extends IStorageManager.Stub
             mHandler.obtainMessage(H_VOLUME_MOUNT, vol).sendToTarget();
 
         } else if (vol.type == VolumeInfo.TYPE_STUB) {
+            if (vol.disk.isStubVisible()) {
+                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE;
+            }
             vol.mountUserId = mCurrentUserId;
             mHandler.obtainMessage(H_VOLUME_MOUNT, vol).sendToTarget();
         } else {