RingtonePlayer: URI userId must match that of caller

Prevent one user from playing media from another user
by checking that the userId of the content matches
the current userId.

Bug: 400434060
Test: atest com.android.systemui.ringtone.RingtonePlayerTest
Flag: android.media.audio.ringtoneUserUriCheck
Change-Id: Ib9a9a8f5049b53ab8bbff5e324988dbc6c7c7c25