Add back face contour model and image labeling model.
Add back face contour model and image labeling model.

It was accidentally removed in
https://devrel-review.git.corp.google.com/c/samples/firebase/quickstart/android/+/116710/1/mlkit/app/build.gradle#b45

Change-Id: I37d991e30cfcd6613dee4215b7782e4edb8610e6

firebase/quickstart-android,firebase/quickstart-android,firebase/quickstart-android,samtstern/quickstart-android,firebase/quickstart-android,samtstern/quickstart-android,samtstern/quickstart-android,firebase/quickstart-android,firebase/quickstart-android