Several managers keep an "int mUserId" field which is assigned from
Context.getUserId(), so Binder calls referencing that field are okay.
Also shift to borrowing the "flavor" logic for detecting userId
parameters consistently.
Bug: 115654727, 159626156
Test: atest error_prone_android_framework_test
Change-Id: I9841fdf16f34c08b113e689e74b94f1ede839e2c
Many system internals pass around PID, UID and user ID arguments as a
single weakly-typed "int" value, which developers can accidentally
cross in method argument lists, resulting in obscure bugs.
Bug: 155703208
Test: atest error_prone_android_framework_test
Change-Id: I5e4d9b5a533071f94d82dff17faff5d52ae54564
