RingtoneManager: verify default ringtone is audio

When a ringtone picker tries to set a ringtone through
RingtoneManager.setActualDefaultRingtoneUri (also
called by com.android.settings.DefaultRingtonePreference),
verify the mimeType can be obtained (not found when caller
doesn't have access to it) and it is an audio resource.

Bug: 205837340
Test: atest android.media.audio.cts.RingtoneManagerTest
Change-Id: I3f2c487ded405c0c1a83ef0a2fe99cff7cc9328e
Merged-In: I3f2c487ded405c0c1a83ef0a2fe99cff7cc9328e
(cherry picked from commit 38618f9fb1)

media/java/android/media/RingtoneManager.java

@@ -833,6 +833,21 @@ public class RingtoneManager {
         if(!isInternalRingtoneUri(ringtoneUri)) {
             ringtoneUri = ContentProvider.maybeAddUserId(ringtoneUri, context.getUserId());
         }
+
+        if (ringtoneUri != null) {
+            final String mimeType = resolver.getType(ringtoneUri);
+            if (mimeType == null) {
+                Log.e(TAG, "setActualDefaultRingtoneUri 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, "setActualDefaultRingtoneUri for URI:" + ringtoneUri
+                        + " ignored: associated mimeType:" + mimeType + " is not an audio type");
+                return;
+            }
+        }
+
         Settings.System.putStringForUser(resolver, setting,
                 ringtoneUri != null ? ringtoneUri.toString() : null, context.getUserId());