Apply user restrictions to add user button

Bug: 213233919
Bug: 207175350
Test: manual, atest com.android.systemui.car.qc
Change-Id: I9c6fb530e5654b4066a102ef8f6f07e8c3892617
Merged-In: I9c6fb530e5654b4066a102ef8f6f07e8c3892617
cherry picked from commit 73a74e64985b7864a8e60c8ab4970992f1107436
2 files changed