(2/2) Fix settings face enrollment UI layout problem

To extract face_enroll_education.xml layout dimensions to dimens.xml
1. Fix settings face enrollment UI truncate problem
2. Fix It's hard to tap "setup for limited vision or head motion"
button

Bug: 260653042
Bug: 263065347

Test: manually go to Settings > Security & privacy > Device lock >
Face & Fingerprint Unlock > Face Unlock, then start enroll Face,
In second stage ("How to set up Face Unlock" page ), check the layout
and lottie animation do not truncate.
Test: m -j SettingsGoogleRoboTests RunSettingsGoogleRoboTests
Test: m RunSettingsRoboTests ROBOTEST_FILTER=
"com.android.settings.biometrics.face.FaceEnrollEducationTest"
Test: m RunSettingsRoboTests ROBOTEST_FILTER=
"com.android.settings.biometrics.face.FaceEnrollIntroductionTest"

Change-Id: I7d7bad8b91dd505772e8f2b28cb4b872a4750cb4