Remove AppCompat library from Contacts (1/3)

This will reduce size of GoogleContacts-N.apk by 0.7 MB (8.4 MB --> 7.7 MB)

* CL was prepared by running the following:

  git revert --no-commit e7fd1ad1 # https://googleplex-android-review.git.corp.google.com/#/c/841451/
  git revert --no-commit 3d53e233 # https://googleplex-android-review.git.corp.google.com/#/c/841473/
  git revert --no-commit 903fbfc4 # https://googleplex-android-review.git.corp.google.com/#/c/839578/

Also:
  - added import view.Window back to PeopleActivity;
  - removed an AppCompat style

Bug 27257097

Change-Id: I21653376c78ef0a435f90b565b6c40dd5b747317