Validate ringtone URIs before setting

Add checks URIs for content from other users.
 Fail for users that are not profiles of the current user.

Test: atest DefaultRingtonePreferenceTest
Bug: 299614635
Change-Id: Ib266b285a3a1c6c5265ae2321159e61e08e349f6

src/com/android/settings/DefaultRingtonePreference.java

@@ -51,16 +51,9 @@ public class DefaultRingtonePreference extends RingtonePreference {
             return;
         }
 
-        String mimeType = mUserContext.getContentResolver().getType(ringtoneUri);
-        if (mimeType == null) {
+        if (!isValidRingtoneUri(ringtoneUri)) {
             Log.e(TAG, "onSaveRingtone for URI:" + ringtoneUri
-                    + " ignored: failure to find mimeType (no access from this context?)");
-            return;
-        }
-
-        if (!(mimeType.startsWith("audio/") || mimeType.equals("application/ogg"))) {
-            Log.e(TAG, "onSaveRingtone for URI:" + ringtoneUri
-                    + " ignored: associated mimeType:" + mimeType + " is not an audio type");
+                    + " ignored: invalid ringtone Uri");
             return;
         }