Map mediaprovider to priv_app in 26.0 compat mapping

Commit: bde5c801 added a new type,
mediaprovider, which is being applied to an object (process) formerly
labeled as priv_app. Add the new type to the versioned attribute for
priv_app so that any vendor policy written for interaction with
mediaprovider continues to work.

Bug: 62573845
Test: None.  Prebuilt-only change.
Change-Id: Id98293369401a2af23c2328a1cb4a5bb2258aac8

prebuilts/api/26.0/26.0.cil

@@ -440,7 +440,7 @@
 (typeattributeset preopt2cachename_26_0 (preopt2cachename))
 (typeattributeset preopt2cachename_exec_26_0 (preopt2cachename_exec))
 (typeattributeset print_service_26_0 (print_service))
-(typeattributeset priv_app_26_0 (priv_app))
+(typeattributeset priv_app_26_0 (mediaprovider priv_app))
 (typeattributeset proc_26_0 (proc))
 (typeattributeset proc_bluetooth_writable_26_0 (proc_bluetooth_writable))
 (typeattributeset proc_cpuinfo_26_0 (proc_cpuinfo))