Scan internal before any external storage.

We've heard reports from partners that we may scan a secondary
external storage device the primary external storage, so change
our logic to scan internal storage in every case to ensure ringtones
are always ready for the user.

Bug: 157001301
Test: atest --test-mapping packages/providers/MediaProvider
Change-Id: Ia74742b58ba5ea1ab430bf5a9046fb3e31fa6fe4
1 file changed