MTP: remove usages of device identifiers with virtual serial number

Improving protection of user privacy
Use randomly generated virtual serial number that persists until factory reset

Bug: 117585389
Test: Open multiple MTP device
	Check MTP device property
	uninstall / re-install MTP driver
	WMP sync with multiple MTP device
	Enable MTP mode with multi-user
	Malformed MTP ID file

Change-Id: I7ed4ce81d9ca1e1c6605c59c73bcd2d26419a5d3

1 files changed, 6 insertions, 1 deletions

diff --git a/media/java/android/mtp/MtpDatabase.java b/media/java/android/mtp/MtpDatabase.java
index 474b671c0c2b..dc2d17753b1d 100755
--- a/media/java/android/mtp/MtpDatabase.java
+++ b/media/java/android/mtp/MtpDatabase.java
@@ -54,6 +54,7 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.IntStream;
 
@@ -248,7 +249,7 @@ public class MtpDatabase implements AutoCloseable {
     public MtpDatabase(Context context, String volumeName,
             String[] subDirectories) {
         native_setup();
-        mContext = context;
+        mContext = Objects.requireNonNull(context);
         mMediaProvider = context.getContentResolver()
                 .acquireContentProviderClient(MediaStore.AUTHORITY);
         mVolumeName = volumeName;
@@ -294,6 +295,10 @@ public class MtpDatabase implements AutoCloseable {
         }
     }
 
+    public Context getContext() {
+        return mContext;
+    }
+
     @Override
     public void close() {
         mManager.close();