Use cached pid uid from Session

Follows existing logic in the class to use cached caller info and
permissions available to the caller. This reduces calls to native
to get pid & uid.

Test: atest CrossAppDragAndDropTests WindowlessWmTests
Bug: 134365580
Change-Id: Ic6203ff645f26f12b50f98ed7649a3a7e7c1326b
1 file changed