Prevent HTML Injection on the Device Admin request screen am: 52f9039d5c am: 6ac45a7ceb am: f470b78ff2

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/14167797

Change-Id: I64550f7d57fd8c4cd2a142188ed78e9bb49f1c9f