Allow subtitle and playlist files in Documents and Downloads

Fix subtitles and playlists handling so that it adds DIRECTORY_MUSIC and
DIRECTORY_MOVIES to the default allowed primary directories, instead of
replacing them.

Test: atest CtsScopedStorageHostTest
Bug: 166057832
Change-Id: I9f3acd3c052390c9fd615b1b3dc9f74efb2c8e5b
diff --git a/src/com/android/providers/media/MediaProvider.java b/src/com/android/providers/media/MediaProvider.java
index 125486f..70656f2 100644
--- a/src/com/android/providers/media/MediaProvider.java
+++ b/src/com/android/providers/media/MediaProvider.java
@@ -2542,17 +2542,17 @@
                         defaultMimeType = "audio/mpegurl";
                         defaultMediaType = FileColumns.MEDIA_TYPE_PLAYLIST;
                         defaultPrimary = Environment.DIRECTORY_MUSIC;
-                        allowedPrimary = Arrays.asList(
-                                Environment.DIRECTORY_MUSIC,
-                                Environment.DIRECTORY_MOVIES);
+                        allowedPrimary = new ArrayList<>(allowedPrimary);
+                        allowedPrimary.add(Environment.DIRECTORY_MUSIC);
+                        allowedPrimary.add(Environment.DIRECTORY_MOVIES);
                         break;
                     case FileColumns.MEDIA_TYPE_SUBTITLE:
                         defaultMimeType = "application/x-subrip";
                         defaultMediaType = FileColumns.MEDIA_TYPE_SUBTITLE;
                         defaultPrimary = Environment.DIRECTORY_MOVIES;
-                        allowedPrimary = Arrays.asList(
-                                Environment.DIRECTORY_MUSIC,
-                                Environment.DIRECTORY_MOVIES);
+                        allowedPrimary = new ArrayList<>(allowedPrimary);
+                        allowedPrimary.add(Environment.DIRECTORY_MUSIC);
+                        allowedPrimary.add(Environment.DIRECTORY_MOVIES);
                         break;
                 }
             } else if (defaultMediaType != actualMediaType) {